Antenna unit and digital television receiver

ABSTRACT

The present invention provides an antenna device comprising a conductive substrate and an antenna element located in the proximity of the conductive substrate, in which a portion of the antenna element is formed of a coil or zigzag conductor and an end of the antenna element is connected to the conductive substrate for grounding. In addition, the coil or zigzag conductor is formed at an end of the antenna element and the coil or zigzag conductor and the other end of the antenna element are connected together on an insulator provided on the conductive substrate.

TECHNICAL FIELD

The present invention relates to an antenna device and in particular, tothe antenna device to be attached to the body of an automobile forreceiving, for example, AM, FM, or TV broadcasting or wireless telephoneor the like.

BACKGROUND ART

With the advance of car multimedia era, in addition to an AM/FM radio,various radio equipment such as a TV receiver, a wireless telephone set,and a navigation system has been recently installed in an automobile.Also hereafter, information and services may be increasingly providedthrough radio wave and the importance of an antenna will growaccordingly.

In general, when the antenna is attached to the automobile and so on,the body configured by a conductive substrate may have some influence onthe antenna performance such as directional gain or the like.Conventional antennas which have been used for automobiles include, forexample, a monopole antenna, a rod antenna, and a V-shaped dipoleantenna, taking account of the attachment to the automobile body. Manyof these antennas, when attached, have a long stick-like antenna elementprotruding on the surface of the automobile body.

As described above, however, such an antenna with a long stick-likeantenna element protruding on the automobile body disfigures theappearance, and furthermore has various other problems such as windsoughing brought about around it, a risk of its being stolen, and laborsinvolved in removing it before car wash.

In view of these problems concerning the conventional antennas, thepresent invention aims to provide an antenna device which can beinstalled in the vicinity of the automobile body or incorporated intothe automobile body to form a plane containing it and can be downsizedenough to be placed in a narrow area, and which is also capable ofcorrectly receiving vertically polarized wave.

And in the recent ground wave digital television broadcasting, thereexists radio disturbance such as frequency-selective fading caused byinterference such as reflected wave from surrounding buildings. Inaddition, for the ground wave digital television broadcasting, in orderto take advantage of the bandwidth effectively, a scheme referred to asSFN has been proposed, which uses a plurality of transmitting stationsto broadcast the same program at the same frequency. This SFNbroadcasting scheme may also result in radio disturbance caused byinterference between signals transmitted by adjacent stations, becausethere exists always a delay time between them.

The present invention has been achieved to solve the problems of radiodisturbance described above and thus provides a digital televisionbroadcasting receiving device which can improve radio disturbance inmovably receiving digital data.

DISCLOSURE OF THE INVENTION

The present invention is an antenna device comprising a conductivesubstrate and an antenna element located in a proximity of saidconductive substrate, wherein a portion of said antenna element isformed of a coil or zigzag conductor and an end of said antenna elementis connected to said conductive substrate for grounding.

The present invention is an antenna device comprising a conductivesubstrate and two or more antenna elements of different lengths locatedin a proximity of said conductive substrate, wherein a portion of eachof said antenna elements is formed of a coil or zigzag conductor and anend of each of said antenna elements is commonly connected to saidconductive substrate for grounding.

The present invention is an antenna device comprising a conductivesubstrate, two or more antenna elements of different lengths located ina proximity of said conductive substrate, and a coil or zigzag conductorconnected to a common connection at an end of each of said antennaelements, wherein the other end of said coil or zigzag conductor isconnected to said conductive substrate for grounding.

The present invention is an antenna device comprising an antenna elementformed of a coil or zigzag conductor as a whole and having at least onebend or curve.

The present invention is an antenna device comprising a conductivesubstrate and an antenna element having an end connected to saidconductive substrate for grounding and located in a proximity of saidconductive substrate, wherein a feeding section is connected to aninsulator provided on said conductive substrate as a relay point.

The present invention is an antenna device comprising a conductivesubstrate and an antenna element having an end connected to saidconductive substrate for grounding and located in the proximity of saidconductive substrate, wherein a through-hole is formed in saidconductive substrate, an insulator is provided an opposite side of saidconductive substrate to said antenna element, at said through-hole, anda feeding section is connected on said insulator by using saidthrough-hole.

The present invention is an antenna device comprising a conductivesubstrate, an antenna element located in a proximity of said conductivesubstrate, and a conductive case provided between said antenna elementand said conductive substrate and having a through-hole in a certainplace, wherein

an end of said antenna element is connected to said conductive case forgrounding, a feeding section is connected to one of a plurality ofinsulators provided on said conductive substrate within said conductivecase by using said through-hole, and circuit components are connectedbetween said plurality of insulators.

The present invention is an antenna device comprising a conductivesubstrate, an insulation plate located in a proximity of said conductivesubstrate, an antenna element formed on said insulation plate at theside farther from said conductive substrate, a conductor running fromsaid antenna element through said insulation plate, and a conductivematerial connected to said conductor and formed on the opposite side ofsaid insulation plate to said antenna element, wherein

an end of said antenna element is connected to said conductive substratefor grounding and a feeding section is connected to said conductivematerial near said grounded antenna element end.

The present invention is an antenna device comprising

a conductive substrate, an insulation plate provided on said conductivesubstrate, a conductive plate provided on said insulation plate andhaving an area smaller than said conductive substrate, and an antennaelement located in a proximity of said conductive plate and having anend connected to said conductive plate for grounding.

The present invention is an antenna device comprising a conductivesubstrate provided with an antenna grounding conductive plate in acertain place thereon and an antenna element located in a proximity ofsaid conductive substrate and having an end connected to said antennagrounding conductive plate.

The present invention is an antenna device comprising

a planar antenna having at least one antenna element having at least onebend or curve and an end connected to a conductive substrate and

a cylindrical antenna located in a proximity of said planar antenna,wherein

an end of said planar antenna is connected to said conductive substrateat a side of said planar antenna farther from said cylindrical antenna.

The present invention is an antenna device comprising

a planar antenna having at least one antenna element having at least onebend or curve and an end connected to a conductive substrate and

a cylindrical antenna located in a proximity of said planar antenna,wherein

an end of said planar antenna is connected to said conductive substrateat a side of said planar antenna closer to said cylindrical antenna.

The present invention is an antenna device comprising a cylindricalantenna provided in a proximity of a conductive substrate and a planarantenna provided between said cylindrical antenna and said conductivesubstrate and having at least one antenna element having at least onebend or curve and an end connected to a conductive substrate.

The present invention is an antenna device comprising

a planar antenna having at least one antenna element having at least onebend or curve and an end connected to a conductive substrate and

a printed antenna located in a proximity of said planar antenna andhaving a zigzag conductive pattern formed on a printed circuit board.

The present invention is an antenna device comprising

a planar antenna having at least one antenna element with at least onebend or curve and a printed antenna having a zigzag conductive pattern,both antennas being formed in a proximity of each other on the sameboard,

a conductive plate connected to an end of said antenna element andcorresponding to said planar antenna, and

an insulation member which insulates said conductive plate from aconductive substrate which is larger than said planar antenna and saidprinted antenna, wherein

said planar antenna, said printed antenna and said conductive plate arecapable to turn together to a direction perpendicular to the plane ofsaid conductive substrate.

The present invention is a digital television broadcasting receivingdevice comprising

an input means which is an antenna device of the present invention asmentioned above,

a delay means for receiving a signal from said input means and delayingit,

a synthesis means for synthesizing a signal from said delay means and asignal from said input means,

a reception means for performing frequency conversion on a signal fromsaid synthesis means, and

a demodulation means for converting a signal from said reception meansinto a baseband signal, wherein

the delay time used in said delay means and the synthesis ratio used insaid synthesis means can be established arbitrarily.

The present invention is a digital television broadcasting receivingdevice comprising

an input means which is an antenna device of the present invention asmentioned above,

a delay means for receiving a signal from said input means and delayingit,

a synthesis means for synthesizing a signal from said delay means and asignal from said input means,

a reception means for performing frequency conversion on a signal fromsaid synthesis means,

a demodulation means for converting a signal from said reception meansinto a baseband signal,

a delayed wave estimation means for receiving a signal indicating thedemodulation conditions from said demodulation means and estimating adelayed wave contained in a signal from said input means, and

a synthesis control means for controlling said synthesis means and saiddelay means in accordance with a signal from said delayed waveestimation means, wherein

either the signal synthesis ratio used in said synthesis means or thedelay time used in said delay means can be controlled in accordance witha signal from said synthesis control means.

The present invention is a digital television broadcasting receivingdevice comprising

an input means which is an antenna device of the present invention asmentioned above,

a reception means for performing frequency conversion on a signal fromsaid input means,

a delay means for receiving a signal from said reception means anddelaying it,

a synthesis means for synthesizing a signal from said delay means and asignal from said reception means, and

a demodulation means for converting a signal from said synthesis meansinto a baseband signal, wherein

the delay time used in said delay means and the synthesis ratio used insaid synthesis means can be established arbitrarily.

The present invention is a digital television broadcasting receivingdevice comprising

an input means which is an antenna device of the present invention asmentioned above,

a reception means for performing frequency conversion on a signal fromsaid input means,

a delay means for receiving a signal from said reception means anddelaying it,

a synthesis means for synthesizing a signal from said delay means and asignal from said reception means,

a demodulation means for converting a signal from said synthesis meansinto a baseband signal,

a delayed wave estimation means for receiving a signal indicating thedemodulation conditions from said demodulation means and estimating adelayed wave contained in a signal from said input means, and

a synthesis control means for controlling said synthesis means and saiddelay means in accordance with a signal from said delayed waveestimation means, wherein

either the signal synthesis ratio used in said synthesis means or thedelay time used in said delay means can be controlled in accordance witha signal from said synthesis control means.

The present invention is a digital television broadcasting receivingdevice comprising

an input means which is an antenna device of the present invention asmentioned above,

a reception means for performing frequency conversion on a signal fromsaid input means,

a demodulation means for converting a signal from said reception meansinto a baseband signal,

a delayed wave estimation means for receiving information on thedemodulation conditions from said demodulation means and estimating adelayed wave contained in a signal from said input means, and

a demodulation control means for controlling said demodulation meansbased on delayed wave information from said delayed wave estimationmeans, wherein

a transfer function to be handled by said demodulation means iscontrolled based on a control signal from said demodulation controlmeans.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an example of an antenna deviceaccording to a first embodiment of the present invention;

FIG. 2 is a schematic diagram showing another example of the antennadevice according to the first embodiment;

FIG. 3 is a schematic diagram showing an example of an antenna deviceaccording to a second embodiment of the present invention;

FIG. 4 is a schematic diagram showing another example of the antennadevice according to the second embodiment;

FIG. 5 is a schematic diagram showing an example of an antenna deviceaccording to a third embodiment of the present invention;

FIG. 6 is a schematic diagram showing another example of the antennadevice according to the third embodiment;

FIG. 7 is a schematic diagram showing another example of the antennadevice according to the third embodiment;

FIG. 8 is a schematic diagram showing another example of the antennadevice according to the third embodiment;

FIG. 9 is a schematic diagram showing an example of an antenna deviceaccording to a fourth embodiment of the present invention;

FIG. 10 is a schematic diagram showing another example of the antennadevice according to the fourth embodiment;

FIG. 11 is a schematic diagram showing another example of the antennadevice according to the fourth embodiment;

FIG. 12 is a schematic diagram showing another example of the antennadevice according to the fourth embodiment;

FIG. 13 is a schematic diagram showing an example of an antenna deviceaccording to a fifth embodiment of the present invention;

FIG. 14 is a schematic diagram showing another example of the antennadevice according to the fifth embodiment;

FIG. 15 is a schematic diagram showing an example of an antenna deviceaccording to a sixth embodiment of the present invention;

FIG. 16 is a schematic diagram showing another example of the antennadevice according to the sixth embodiment;

FIG. 17 is a schematic diagram showing another example of the antennadevice according to the sixth embodiment;

FIG. 18 is a schematic diagram showing an example of the antenna deviceaccording to the sixth embodiment;

FIG. 19 is a schematic diagram showing an example of an antenna deviceaccording to a seventh embodiment of the present invention;

FIG. 20 is a schematic diagram showing another example of the antennadevice according to the seventh embodiment;

FIG. 21 is a schematic diagram showing another example of the antennadevice according to the seventh embodiment;

FIG. 22 is a schematic diagram showing an example of an antenna deviceaccording to an eighth embodiment of the present invention;

FIG. 23 is a schematic diagram showing another example of the antennadevice according to the eighth embodiment;

FIG. 24 shows the positional relationship between the antenna and theconductive substrate in the antenna device according to the eighthembodiment;

FIG. 25 is a schematic diagram showing an example of an antenna deviceaccording to a ninth embodiment of the present invention;

FIG. 26 is a schematic diagram showing a n example of an antenna deviceaccording to a tenth embodiment of the present invention;

FIG. 27 is a schematic diagram showing an example of an antenna deviceaccording to an eleventh embodiment of the present invention;

FIG. 28 is a schematic diagram showing another example of the antennadevice according to the eleventh embodiment;

FIG. 29 is a schematic diagram showing an example of an antenna deviceaccording to a twelfth embodiment of the present invention;

FIG. 30 is a schematic diagram showing an example of an antenna deviceaccording to a thirteenth embodiment of the present invention;

FIG. 31 is a schematic diagram showing an example of an antenna deviceaccording to a fourteenth embodiment of the present invention;

FIG. 32 is a schematic diagram showing an example of an antenna deviceaccording to a fifteenth embodiment of the present invention;

FIG. 33 is a schematic diagram showing another example of the antennadevice according to the fifteenth embodiment;

FIG. 34 is a schematic diagram showing an example of an antenna deviceaccording to a sixteenth embodiment of the present invention;

FIG. 35 is a schematic diagram showing an example of an antenna deviceaccording to a seventeenth embodiment of the present invention;

FIG. 36 is a perspective view showing a example of locations where anantenna device according to an eighteenth embodiment of the presentinvention is to be installed;

FIG. 37 is a perspective view showing another example of locations wherethe antenna device according to the eighteenth embodiment is to beinstalled;

FIG. 38 is a schematic diagram showing an example of a mobilecommunication device with an antenna device according to a nineteenthembodiment of the present invention;

FIG. 39 is a schematic diagram showing an example of a portabletelephone with an antenna device according to a twentieth embodiment ofthe present invention;

FIG. 40 shows an example of band synthesis according to the presentinvention;

FIG. 41 shows an example of gain accumulation according to the presentinvention;

FIG. 42 is a schematic diagram showing an antenna device according to atwenty-first embodiment of the present invention;

FIG. 43 is a schematic diagram showing another example of the antennadevice according to the twenty-first embodiment;

FIG. 44 is a schematic diagram showing an example of an antenna deviceaccording to a twenty-second embodiment of the present invention;

FIG. 45 is a schematic diagram showing an example of an antenna deviceaccording to a twenty-third embodiment of the present invention;

FIG. 46 is a schematic diagram showing an example of an antenna deviceaccording to a twenty-fourth embodiment of the present invention;

FIG. 47 is a perspective view showing a possible automobile applicationof an antenna device according to a twenty-fifth embodiment of thepresent invention;

FIG. 48 is a perspective view showing possible locations where anantenna according to a twenty-sixth embodiment of the present inventionis to be installed for automobile applications;

FIG. 49 is a schematic diagram for explaining the properties of theantenna according to the twenty-sixth embodiment;

FIG. 50 is a schematic diagram showing the configuration of an antennaaccording to a twenty-seventh embodiment of the present invention;

FIG. 51 is a schematic diagram showing another configuration of theantenna according to the twenty-seventh embodiment;

FIG. 52 is a schematic diagram showing possible locations where theantenna according to the twenty-seventh embodiment is to be installedfor automobile applications;

FIG. 53 is a schematic diagram showing a possible application to aportable telephone of the antenna according to the twenty-seventhembodiment;

FIG. 54 is a schematic diagram showing a possible application to anordinary house of the antenna according to the twenty-seventhembodiment;

FIG. 55 is a schematic diagram showing the configuration of an antennaaccording to a twenty-eighth embodiment of the present invention;

FIG. 56 (a) is a schematic diagram showing the configuration of anotherexample of the antenna according to the twenty-eighth embodiment andFIG. 56 (b) is an explanatory drawing therefor;

FIG. 57 is a schematic diagram showing the configuration of an exampleof an antenna according to a twenty-ninth embodiment of the presentinvention;

FIG. 58 is a schematic diagram showing the configuration of anotherexample of the antenna according to the twenty-ninth embodiment;

FIG. 59 is a schematic diagram showing the configuration of stillanother example of the antenna according to the twenty-ninth embodiment;

FIGS. 60 (a) and 60(b) are schematic diagrams showing the configurationof an example of an antenna according to a thirtieth embodiment of thepresent invention and FIG. 60 (c) is a graph for explaining thefrequency characteristics thereof;

FIGS. 61(a) and 61(b) are schematic diagrams showing the configurationof another example of the antenna according to the thirtieth embodimentand FIG. 61(c) is a graph for explaining the frequency characteristicsthereof;

FIGS. 62(a) and 62(b) are schematic diagrams showing the configurationof still another example of the antenna according to the thirtiethembodiment and FIG. 62(c) is a graph for explaining the frequencycharacteristics thereof;

FIG. 63 shows an application of the antenna device according to thetwenty-ninth embodiment;

FIG. 64 shows another application of the antenna device according to thetwenty-ninth embodiment;

FIG. 65 shows still another application of the antenna device accordingto the twenty-ninth embodiment;

FIG. 66 shows still another application of the antenna device accordingto the twenty-ninth embodiment;

FIG. 67 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-first embodiment of the presentinvention;

FIG. 68 is a schematic diagram showing the configuration of anotherexample of the antenna according to the thirty-first embodiment;

FIG. 69 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-second embodiment of the presentinvention;

FIG. 70 is a schematic diagram showing the configuration of anotherexample of the antenna according to the thirty-second embodiment;

FIG. 71 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-third embodiment of the presentinvention;

FIG. 72 is a schematic diagram showing the configuration of anotherexample of the antenna according to the thirty-third embodiment;

FIG. 73 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-fourth embodiment of the presentinvention;

FIG. 74 is a schematic diagram showing the configuration of anotherexample of the antenna according to the thirty-fourth embodiment;

FIG. 75 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-fifth embodiment of the presentinvention;

FIG. 76 is a schematic diagram showing the configuration of anotherexample of the antenna according to the thirty-fifth embodiment;

FIG. 77 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-sixth embodiment of the presentinvention;

FIG. 78 is a schematic diagram showing another pattern according to thethirty-sixth embodiment;

FIG. 79 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-seventh embodiment of the presentinvention;

FIG. 80 is a schematic diagram showing the configuration of anotherexample of the antenna according to the thirty-seventh embodiment;

FIG. 81 is a schematic diagram showing the configuration of stillanother example of the antenna according to the thirty-seventhembodiment;

FIG. 82 is a schematic diagram showing the configuration of stillanother example of the antenna according to the thirty-seventhembodiment;

FIG. 83 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-eighth embodiment of the presentinvention;

FIG. 84 is a schematic diagram showing the configuration of an exampleof an antenna according to a thirty-ninth embodiment of the presentinvention;

FIG. 85 is a perspective view showing a specific configuration of theantenna device shown in FIG. 2;

FIG. 86 shows the impedance and VSWR characteristics of the antennashown in FIG. 85;

FIG. 87 shows the directional gain characteristics of the antenna shownin FIG. 85;

FIG. 88 shows the VSWR characteristics of an element for explaining bandsynthesis in a 4-element antenna;

FIG. 89 shows the VSWR characteristics of another element for explainingband synthesis in the 4-element antenna;

FIG. 90 shows the VSWR characteristics of still another element forexplaining band synthesis in the 4-element antenna;

FIG. 91 shows the VSWR characteristics of still another element forexplaining band synthesis in the 4-element antenna;

FIG. 92 shows the VSWR characteristics after band synthesis of the4-element antenna shown in FIGS. 88 through 91;

FIG. 93 shows the VSWR characteristics when the range of ordinates inFIG. 92 is extended;

FIG. 94 shows the directional gain characteristics when the antennaground is located at different distances from the device ground in theantenna of FIG. 44(b);

FIG. 95 shows the directional gain characteristics in the antenna ofFIG. 55(a);

FIG. 96 shows the directional gain characteristics in the antenna ofFIG. 55(b);

FIG. 97 is a schematic diagram showing an example of an antenna deviceaccording to a fortieth embodiment of the present invention;

FIG. 98 is a schematic diagram showing another example of the antennadevice according to the fortieth embodiment;

FIG. 99 is a schematic diagram showing an example of an antenna deviceaccording to a forty-first embodiment of the present invention;

FIG. 100 is a schematic diagram showing another example of the antennadevice according to the forty-first embodiment;

FIG. 101 is a schematic diagram showing an example of an antenna deviceaccording to a forty-second embodiment of the present invention;

FIG. 102 is a schematic diagram showing another example of the antennadevice according to the forty-second embodiment;

FIG. 103 is a schematic diagram showing an example of an antenna deviceaccording to a forty-third embodiment of the present invention;

FIG. 104 is a schematic diagram showing another example of the antennadevice according to the forty-third embodiment;

FIG. 105 is a schematic diagram showing an example of an antenna deviceaccording to a forty-fourth embodiment of the present invention;

FIG. 106 is a schematic diagram showing other possible forms of theantenna according to the forty-fourth embodiment;

FIG. 107 is a schematic diagram showing other possible patterns of theantenna according to the forty-fourth embodiment;

FIG. 108 is a schematic diagram showing an example of an antenna deviceaccording to a forty-fifth embodiment of the present invention;

FIG. 109 is a schematic diagram showing an example of an antenna deviceaccording to a forty-sixth embodiment of the present invention;

FIG. 110 is a schematic diagram showing another example of the antennadevice according to the forty-sixth embodiment;

FIG. 111 is a schematic diagram showing still another example of theantenna device according to the forty-sixth embodiment;

FIG. 112 is a schematic diagram showing an example of an antenna deviceaccording to a forty-seventh embodiment of the present invention;

FIG. 113 is a schematic diagram showing another example of the antennadevice according to the forty-seventh embodiment;

FIG. 114 is a schematic diagram showing still another example of theantenna device according to the forty-seventh embodiment;

FIG. 115 is a schematic diagram showing other possible forms of theantenna according to the forty-seventh embodiment;

FIG. 116 is a schematic diagram showing still another example of theantenna device according to the forty-seventh embodiment;

FIG. 117 is a schematic diagram showing an example of an antenna deviceaccording to the forty-eighth embodiment of the present invention;

FIG. 118 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to an embodiment ofthe present invention;

FIG. 119 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to another embodimentof the present invention;

FIG. 120 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to still anotherembodiment of the present invention;

FIG. 121 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to still anotherembodiment of the present invention;

FIG. 122 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to still anotherembodiment of the present invention;

FIG. 123 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to still anotherembodiment of the present invention;

FIG. 124 shows the result of frequency analysis performed on a receivedsignal which is affected by disturbance of a delayed wave;

FIG. 125 shows the gain control performed by a synthesis means;

FIG. 126 shows the delay time and error rate of a delayed wave; and

FIG. 127 is a flow chart for explaining antenna switching conditions forchanging over from one antenna to another.

DESCRIPTION OF SYMBOLS

101, 104 Antenna element (linear conductor)

102 Feeding terminal

151 Conductive substrate

152 Monopole antenna

153 Feeding section

154 Antenna element

155 Feeding section

205 Conductive substrate

254, 255 Antenna element

256, 257 Reactance

258 Feeding section

502, 504 Reactance element

1304 Printed circuit board

1505 Recess

1806 Multilayer printed circuit board

1901 Feeding point

3003 Dielectric

3203 Coil

3503 Diversity changeover switch

3804 Communication device

3804 Body

3902 Shield case

4603 High-permittivity material

5603, 5606 Ferroelectric

9001 Input means

9002 Delay means

9003 Synthesis means

9004 Reception means

9005 Demodulation means

9006 Synthesis control means

9007 Delayed wave estimation means

9008 Positional information determination means

9009 Vehicle information detection means

9011 Antenna

9012 Amplification means

9061 Gain control means

9062 Delay time control means

9091 Speed detection means

9092 Position detection means

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the present invention will be described below with respect to theaccompanying drawings which show embodiments thereof.

To begin with, the principle of those embodiments will be described. Asdescribed in the section “BACKGROUND ART” above, when a conventionalantenna like a monopole antenna is installed in the proximity to aconductive substrate, the body configured by the conductive substratemay have some influence on the antenna performance such as directionalgain. By taking advantage of such an influence of the conductivesubstrate on the antenna, the present invention can implement ahigh-selectivity antenna with no directivity and an improved directionalgain.

(Embodiment 1)

FIG. 1 is a schematic diagram showing the configuration of an antennadevice according to a first embodiment of the present invention. Namely,FIG. 1(a) shows an antenna device which comprises an antenna element 101configured by a linear conductor with two bends, a feeding terminal 102provided in place on the antenna element 101, and a grounded end 103.FIG. 1(b) shows antenna device which comprises an antenna element 104configured by a linear conductor with four bends, a feeding terminal 102provided in place on the antenna element 104, and a grounded end 103. Inthis way, the antenna devices according to the present embodiment canreduce the installation area because the antenna elements of themonopole antennas are bent.

FIG. 2 is a schematic diagram showing such example that antenna deviceshaving the configurations similar to those described above are locatedin the proximity to conductive substrates, respectively. Namely, FIG.2(a) shows an antenna device which comprises an antenna element 201configured by a linear conductor with two bends and located in theproximity to a conductive substrate 205 with the antenna plane parallelto the substrate, a feeding terminal 202 provided in place on theantenna element 201, and an end 203 connected to the conductivesubstrate 205 for grounding. FIG. 2(b) shows another antenna devicewhich comprises an antenna element 204 configured by a linear conductorwith four bends and located in the proximity to a conductive substrate205 with the antenna plane parallel to the substrate, a feeding terminal202 provided in place on the antenna element 204, and an end 203connected to the conductive substrate 205 for grounding. In this way,the antenna devices according to the present embodiment can reduce theinstallation area as well as improve their directional gain performancebecause the antenna devices according to the first embodiment asdescribed above are located in the proximity to the conductivesubstrates with their antenna planes parallel to the conductivesubstrates 205, respectively. It should be noted that the number ofbends in an antenna element is not limited to that described withrespect to the above embodiment. This may also apply to succeedingembodiments described below.

A specific configuration of the antenna of FIG. 2(a) is shown in FIG.85. In FIG. 85, an antenna element 8501 configured by a linear conductorwith two bends is located at a distance from a conductive substrate 8504with the antenna plane almost parallel to the substrate and an end ofthe antenna element 8501 is connected to an end of a conductive plate8503 provided almost perpendicular to the conductive substrate 8504 forantenna grounding. It should be noted that, in this case, the areaformed by the antenna element 8501 is almost equal to that of theconductive substrate 8504. It should be also noted that a feedingsection 8502 is provided in the way of the antenna element 8501.

The conductive plate 8503 has a width sufficiently larger than that ofthe antenna element 8501, that is, a width which may not be practicallyaffected by any reactance determined from the tuning frequency of theantenna element 8501. This allows the conductive plate to serve as aground. A smaller width may cause the conductive plate to couple to theantenna element 8501 thus to form a single antenna element as a wholeswhich will deviate from the scope of the present invention. The antennaelement 8501 is, for example, 220 mm long and 2 mm wide for a wavelengthof 940 mm and this may make the antenna device more compact. It shouldbe noted that the antenna plane and the conductive substrate plane maybe tilted to the extent that there exists an effective potentialdifference between the antenna element and the substrate. It should bealso noted that if the area of the conductive substrate is larger thanthat of the antenna plane (for example, by quadruple), the gain mayremain unchanged for a vertically polarized wave but decrease for ahorizontally polarized wave.

The antenna according to the present embodiment differs fromconventional antennas in that, for example, a smaller distance betweenthe antenna element and the ground plate may degrade the performance ofa conventional inverted F-shaped antenna, while such a smaller distancemay improve the performance of the antenna according to the presentinvention.

The impedance and VSWR characteristics of the antenna of FIG. 85 areshown in FIG. 86. Its directional gain characteristics are shown in FIG.87. As shown in FIG. 87, the antenna of FIG. 85 has a generally circulardirectivity with respect to a vertically polarized wave.

Needless to say, the shape and number of antenna elements are notlimited to those described with respect to the above embodiment.

It should be more preferable that the distance between the conductivesubstrate and the antenna element is a fortieth of the wavelength ormore.

(Embodiment 2)

FIG. 3 is a schematic diagram showing the configuration of an antennadevice according to a second embodiment of the present invention.Namely, FIG. 3(a) shows an antenna device which comprises an antennaelement 301 configured by being a dipole antenna configured by a linearconductor with four bends, a feeding terminal 302 provided in place onthe antenna element 301, and a grounded point 303. FIG. 3(b) showsanother antenna device which comprises an antenna element 304 configuredby being a dipole antenna configured by a linear conductor with eightbends, a feeding terminal 302 provided in place on the antenna element304, and a grounded point 303. In this way, the antenna devicesaccording to the present embodiment can reduce the installation areabecause the antenna elements of the dipole antennas are bent like awinding.

FIG. 4 is a schematic diagram showing that antenna devices having theconfigurations similar to those described above are located in theproximity to conductive substrates, respectively. Namely, FIG. 4(a)shows an antenna device which comprises an antenna element 401configured to be a dipole antenna configured by a linear conductor withfour bends and located in the proximity to a conductive substrate 405with the antenna plane parallel to the substrate, a feeding terminal 402provided in place on the antenna element 401, and a point 403 connectedto the conductive substrate 405 for grounding. FIG. 4(b) shows anotherantenna device which comprises an antenna element 404 configured bybeing a dipole antenna configured by a linear conductor with eight bendsand located in the proximity to a conductive substrate 405 with theantenna plane parallel to the substrate, a feeding terminal 402 providedin place on the antenna element 401, and a point 403 connected to theconductive substrate 405 for grounding. In this way, the antenna devicesaccording to the present embodiment can reduce the installation area aswell as further improve their directional gain performance when theantenna devices are located in the proximity to the conductivesubstrates with their antenna planes parallel to the conductivesubstrates 405, respectively.

(Embodiment 3)

FIG. 5 is a schematic diagram showing the configuration of an antennadevice according to a third embodiment of the present invention. Namely,FIG. 5(a) shows an antenna device which comprises three monopole antennaelements 501 a, 501 b, and 501 c having two bends and different lengthsand being located on the same plane, and reactance elements 502 a, 502b, 502 c, and 504 connected between the taps of the antenna elements 501a, 501 b, and 501 c and a feeding terminal 503 and between the feedingterminal 503 and a ground terminal 505, respectively, to adjust theirimpedance. FIG. 5(b) shows another antenna device which substitutesantenna elements 506 a, 506 b, and 506 c having four bends for theantenna elements 501 a, 501 b, and 501 c of the antenna device of FIG.5(a) described above.

With the configurations described above, an antenna device having adesirable bandwidth can be implemented by setting the tuning frequenciesof the antenna elements at regular intervals. FIG. 40 shows an exampleof band synthesis performed by an antenna having seven antenna elementsand it may be seen from the figure that a broadband frequencycharacteristic can be achieved through such band synthesis even wheneach antenna element has a small bandwidth.

Specific examples of such band synthesis will be described with respectto the VSWR characteristics shown in FIGS. 88 through 93. Namely, theseexamples use four antenna elements with different tuning frequencies,that is, 196.5 MHz (FIG. 88), 198.75 MHz (FIG. 89), 200.5 MHz (FIG. 90),and 203.75 MHz (FIG. 91), respectively. FIG. 92 shows the VSWRcharacteristics after band synthesis of these antenna elements and itcan be seen that the band has become wider than before. FIG. 93 showsthe VSWR characteristics when the range of ordinates in FIG. 92 isextended (by quintuple).

FIG. 6 is a schematic diagram showing that antenna devices having theconfigurations similar to those of FIG. 5 described above are located inthe proximity to conductive substrates, respectively. In the figure,antenna devices having the configurations similar to those of FIG. 5described above are located in the proximity to conductive substrates607 with their antenna planes parallel to the substrates. Namely, FIG.6(a) shows an antenna device which comprises three monopole antennaelements 601 a, 601 b, and 601 c having two bends and different lengthsand being located on the same plane in the proximity to a conductivesubstrate 607, and reactance elements 602 a, 602 b, 602 c, and 604connected between the taps of the antenna elements 601 a, 601 b, and 601c and a feeding terminal 603 and between the feeding terminal 603 and aground terminal 605, respectively, to adjust their impedance. FIG. 6(b)shows another antenna device which substitutes antenna elements 606 a,606 b, and 606 c having four bends for the antenna elements 601 a, 601b, and 601 c of the antenna device of FIG. 6(a) described above.

FIG. 7 is a schematic diagram showing the configuration of still anotherexample of the antenna device according to the present embodiment.Namely, FIG. 7(a) shows that reactance elements 708 a and 708 b for bandsynthesis are provided between antenna elements 701 a, 701 b, and 701 cin an antenna device having the configuration similar to that of FIG.5(a) described above. FIG. 7(b) shows that reactance elements 708 a and708 b for band synthesis are provided between antenna elements 706 a,706 b, and 706 c in an antenna device having the configuration similarto that of FIG. 5(b) described above. While in the configurations ofFIGS. 5(a) and (b), each reactance element 502 a, 502 b, or 502 cperforms the band synthesis in addition, the present embodiment canfacilitate the impedance adjustment and band synthesis because the bandsynthesis function is separated from the impedance adjustment.

FIG. 8 is a schematic diagram showing the configuration of still anotherexample of the antenna device according to the present embodiment. Inthe figure, antenna devices having the configurations similar to thoseof FIG. 7 described above are located in the proximity to conductivesubstrates 807 with their antenna planes parallel to the substrates.Namely, FIG. 8(a) shows that reactance elements 808 a and 808 b for bandsynthesis are provided between antenna elements 801 a, 801 b, and 801 cin an antenna device having the configuration similar to that of FIG.6(a) described above. FIG. 8(b) shows that reactance elements 808 a and808 b for band synthesis are provided between antenna elements 806 a,806 b, and 806 c in an antenna device having the configuration similarto that of FIG. 6(b) described above.

(Embodiment 4)

FIG. 9 is a schematic diagram showing the configuration of an antennadevice according to a fourth embodiment of the present invention.Namely, FIG. 9(a) shows an antenna device which comprises three dipoleantenna elements 901 a, 901 b, and 901 c having four bends and differentlengths and being located on the same plane, and reactance elements 902a, 902 b, 902 c, and 904 connected between the taps of the antennaelements 901 a, 901 b, and 901 c and a feeding terminal 903 and betweenthe feeding terminal 903 and a ground terminal 905, respectively, toadjust their impedance. FIG. 9(b) shows another antenna device whichsubstitutes antenna elements 906 a, 906 b, and 906 c having eight bendsfor the antenna elements 901 a, 901 b, and 901 c of the antenna deviceof FIG. 9(a) described above.

With the configurations described above, an antenna device having adesirable bandwidth can be implemented by setting the tuning frequenciesof the antenna elements at regular intervals.

FIG. 10 is a schematic diagram showing the configuration of anotherexample of the antenna device according to the present embodiment. Inthe figure, antenna devices having the configurations similar to thoseof FIG. 9 described above are located in the proximity to conductivesubstrates 1007 with their antenna planes parallel to the substrates.Namely, FIG. 10(a) shows an antenna device which comprises three dipoleantenna elements 1001, 1002, and 1003 having four bends and differentlengths and being located on the same plane in the proximity to aconductive substrate 1007, and reactance elements 1004, 1005, 1006, and1009 connected between the taps of the antenna elements 1001, 1002, and1003 and a feeding terminal 1008 and between the feeding terminal 1008and a ground terminal 1010, respectively, to adjust their impedance.FIG. 10(b) shows another antenna device which substitutes antennaelements 1011, 1012, and 1013 having eight bends for the antennaelements 1001, 1002, and 1003 of the antenna device of FIG. 10(a)described above.

FIG. 11 is a schematic diagram showing the configuration of stillanother example of the antenna device according to the presentembodiment. Namely, FIG. 11(a) shows that additional reactance elements1114, 1115, 1116, and 1117 for band synthesis are provided betweenantenna elements 1101, 1102, and 1103 at two separate locations in anantenna device having the configuration similar to that of FIG. 9(a)described above. FIG. 11(b) shows that reactance elements 1114, 1115,1116, and 1117 for band synthesis are provided between antenna elements1111, 1112, and 1113 at two separate locations in an antenna devicehaving the configuration similar to that of FIG. 9(b) described above.While in the configurations of FIGS. 9(a) and (b), each reactanceelement 902 a, 902 b, or 902 c performs the band synthesis in addition,the present embodiment can facilitate the impedance adjustment and bandsynthesis because the band synthesis function is separated from theimpedance adjustment.

FIG. 12 is a schematic diagram showing the configuration of stillanother example of the antenna device according to the presentembodiment. In the figure, antenna devices having the configurationssimilar to those of FIG. 11 described above are located in the proximityto conductive substrates 1207 with their antenna planes parallel to thesubstrates. Namely, FIG. 12(a) shows that reactance elements 1214, 1215,1216, and 1217 for band synthesis are provided between antenna elements1201, 1202, and 1203 at two separate locations in an antenna devicehaving the configuration similar to that of FIG. 10(a) described above.FIG. 12(b) shows that reactance elements 1214, 1215, 1216, and 1217 forband synthesis are provided between antenna elements 1211, 1212, and1213 at two separate locations in an antenna device having theconfiguration similar to that of FIG. 10(b) described above.

(Embodiment 5)

FIG. 13 is a schematic diagram showing the configuration of an antennadevice according to a fifth embodiment of the present invention. Namely,FIG. 13(a) shows an antenna device which comprises three dipole antennaelements 1301, 1302, and 1303 having different lengths and being formedon a printed circuit board 1304. FIG. 13(b) shows another antenna deviceof the configuration similar to that of FIG. 13(a) described above,which has a conductive substrate 1308 formed on the opposite side of theprinted circuit board 1304 to the antenna element 1320. Such aconfiguration where a printed circuit board is used to form the antennaelements 1301, 1302, and 1303 (1305, 1306, 1307) and the conductivesubstrate 1308 can save the space necessary for an antenna as well asallow easy fabrication of the antenna with improved performancereliability and stability.

FIG. 14 is a schematic diagram showing the configuration of anotherexample of the antenna device according to the present embodiment. Inthe figure, antenna devices of the configurations similar to those ofFIG. 13(a) described above have a conductor for band analysis formed onthe opposite side of a printed circuit board to antenna elements in adirection perpendicular to the antenna elements. Namely, FIG. 14(a)shows an antenna device which comprises three dipole antenna elements1401, 1402, and 1403 having different lengths and being formed on aprinted circuit board 1404 and two conductors 1405 formed on theopposite side of the printed circuit board 1404 to the antenna element1410 in a direction perpendicular to the antenna element. FIG. 14(b)shows another antenna device of the configuration similar to that ofFIG. 14(a) described above, which has a conductive substrate 1406located in close proximity on the opposite side to the antenna element1410. This conductive substrate 1406 may be formed on the printedcircuit board through a multilayer printing technique. The configurationdescribed above can allow easy fabrication of elements for bandsynthesis.

(Embodiment 6)

FIG. 15 is a schematic diagram showing the configuration of an antennadevice according to a sixth embodiment of the present invention. Theantenna device according to the present embodiment has antenna elements1501, 1502, and 1503 located within a recess 1505 in a conductivesubstrate 1504. This configuration can eliminate any protrusion from anautomobile body and improve the directional gain performance throughinteraction between the edge of the antenna element 1510 and theconductive substrate 1504.

FIG. 16 is a schematic diagram showing the configuration of anotherexample of the antenna device according to the present embodiment. Theantenna device of FIG. 16(a) comprises an antenna 1610 consisting ofantenna elements 1601, 1602, and 1603 and an antenna 1620 consisting ofantenna elements 1606, 1607, and 1608 and these antennas 1610 and 1620are located in the same plane and within a recess 1605 in a conductivesubstrate 1604. It should be noted that the antennas 1610 and 1620 ofthe present embodiment are different from each other in size and shapebut they may be of the same size and shape. Feeding sections of theseantennas are located in the proximity of each other. FIG. 16(b) showsthat a similar antenna is located in the proximity of a planarconductive substrate 1609.

FIG. 17 is a schematic diagram showing the configuration of stillanother example of the antenna device according to the presentembodiment. The antenna device of FIG. 17(a) comprises an upper antenna1710 consisting of antenna elements 1701, 1702, and 1703 and a lowerantenna 1720 also consisting of antenna elements 1701, 1702, and 1703and these antennas 1710 and 1720 are located at two levels and within arecess 1705 in a conductive substrate 1704. It should be noted that theantennas 1710 and 1720 of the present embodiment are of the same sizeand shape but they may be different from each other in size and shape.FIG. 17(b) shows an example that a similar antenna is located in theproximity of a planar conductive substrate 1706. If the antenna elementsare of the same size, they will have the same tuning frequency.Therefore, the bandwidth of the whole antenna device is the same as thatof a single element but the present embodiment can implement a high-gainand high-selectivity antenna because the overall gain of the antennadevice can be improved as compared with a single-element implementationby accumulating the gain of each antenna element, as shown FIG. 41.

FIG. 18 is a schematic diagram showing the configuration of stillanother example of the antenna device according to the presentembodiment. The antenna device of FIG. 18(a) comprises three antennas1801, 1802, and 1803 each having one or more bends and a plurality ofdipole antenna elements and these antennas are formed to be a multilayerprinted circuit board 1806 and located within a recess 1805 in aconductive substrate 1804. It should be noted that the three antennas1801, 1802, and 1803 of the present embodiment are of the same size andshape but they may be different from each other in size and shape. Itshould be also noted that the three antennas are layered in the presentembodiment but four or more antennas may be layered. FIG. 18(b) showsthat a similar antenna is located in the proximity of a planarconductive substrate 1807. As described above, the present embodimentcan implement a high-gain and high-selectivity antenna easily by forminga plurality of antennas as a multilayer printed circuit board.

(Embodiment 7)

FIG. 19 is a schematic diagram showing the configurations of twoexamples of an antenna according to a seventh embodiment of the presentinvention. The antenna according to the present embodiment has twolinear conductors each having four bends and these conductors arelocated opposite to each other with respect to a feeding section.Namely, FIG. 19(a) shows an antenna device similar to that of FIG. 3(b)described above, which has two linear conductors 1902 and 1903 bendingin opposite directions to each other with respect to a feeding point1901 and FIG. 19(b) shows another antenna device which has two linearconductors 1904 and 1905 bending in the same direction with respect to afeeding point 1901. This shape can allow implementation of a compactplanar nondirectional antenna.

FIG. 20(a) shows an antenna device having an antenna element 2002 inwhich the length between a feeding section 2001 and a first bend P isrelatively longer than the length between the first bend P and a secondbend Q. FIG. 20(b) shows an antenna device having an antenna element2002 in which the length between a feeding section 2001 and a first bendP is relatively shorter than the length between the first bend P and asecond bend Q. This shape can allow the antenna device to be installedin a narrow area.

It should be noted that the present embodiment has two linear conductorslocated opposite to each other with respect to a feeding section but thenumber of linear conductors is not limited to that of the presentembodiment and may be only one. In addition, the number of bends is notlimited to that of the present embodiment.

It should be noted that the present embodiment has two linear conductorslocated opposite to each other with respect to a feeding section but thenumber of linear conductors is not limited to that of the presentembodiment and may be only one. In addition, the number of bends is notlimited to that of the present embodiment.

It should be also noted that the linear conductors in the presentembodiment are bent but they may be curved or spiralled. For example, asshown in FIG. 21(a), the present embodiment may have two linearconductors 2102 and 2103 curving in opposite directions to each otherwith respect to a feeding section 2101 or two linear conductors 2104 and2105 curving in the same direction with respect to a feeding section2101. Also, as shown in FIG. 21(b), the present embodiment may have twolinear conductors 2106 and 2107 spiralling in opposite directions toeach other with respect to a feeding section 2101 or two linearconductors 2108 and 2109 spiralling in the same direction with respectto a feeding section 2101.

When an antenna according to the present embodiment is fabricated, anantenna element can be formed, of course, by working metal members butit may be formed through printed-wiring on a circuit board. Such aprinted-wiring technique can allow easy fabrication of an antenna aswell as provide a more reliable compact antenna at a reduced cost.

The antenna according to the present embodiment may also apply tosucceeding embodiments described below.

(Embodiment 8)

FIG. 22 is a schematic diagram showing the configuration of an exampleof an antenna device according to an eighth embodiment of the presentinvention. The antenna device according to the present embodiment islocated in the proximity of a conductive substrate with its groundterminal connected to the substrate. For example, as shown in FIG.22(a), an antenna element 2201 is located in the proximity of asubstrate 2204 with its ground terminal 2203 connected to the substrate2204. It should be noted that this antenna device is similar to that ofFIG. 4(b) but differs in that a feeding terminal 2202 is provided atsuch position via a through-hole of the conductive substrate 2204. Sucha configuration can provide a desired impedance characteristic anddirectivity.

FIG. 22(b) shows that a switching element is provided between a groundterminal and a conductive substrate in the antenna. As shown in thefigure, a switching element 2205 is provided between a ground terminal2203 of an antenna element 2201 and a conductive substrate 2204 toselect such state that can effect the optimum radio-wave propagationamong such cases whether the ground terminal is connected to theconductive substrate or not. For this purpose, the switching element2205 may be remotely operated to control the antenna device depending onthe state of a received wave. The antenna device of the presentembodiment is used for a vertically polarized wave if the groundterminal 2203 is connected to the substrate, while it is used for ahorizontally polarized wave if the ground terminal is not connected tothe substrate.

It should be noted that the feeding terminal 2202 is via a through-holeof the conductive substrate 2204 in FIG. 22(b) but its location is notlimited to this embodiment and that, as shown in FIG. 23, a feedingterminal 2302 and a ground terminal 2303 may be not penetrating theconductive substrate 2304.

FIG. 24 shows the positional relationship between the antenna and theconductive substrate according to the present embodiment. As shown inFIG. 24(a), a plane of a conductive substrate 2402 and a plane of anantenna 2401 are located parallel to each other at a distance of h. Thedirectivity of the antenna 2401 can be changed to a desired direction bycontrolling the distance h. The tuning frequency is raised if theantenna 2401 is closer to the conductive substrate 2402, while thetuning frequency is lowered if the antenna is further distant from thesubstrate. Therefore, the antenna device may be configured to controlthe distance h depending on the state of a received wave of thepropagation. The control of the distance h may be accomplished, forexample, by using a feed or slide mechanism (not shown) to move theantenna 2401 in a direction perpendicular to the antenna plane or byinserting an insulation spacer (not shown) between the antenna 2401 andthe conductive substrate 2402 and moving the spacer in a directionparallel to the antenna plane to adjust the length of the spacerinsertion. Also, the size of the spacer may be determined to obtain adesired antenna performance during the fabrication of the antenna. Itshould be noted that a spacer between the substrate and the antenna maybe made of a low-permittivity material such as expanded styrol.

As shown in FIG. 24(b), the plane of the conductive substrate 2402 andthe plane of the antenna 2403 may be located in a 3 D dimension to forma predetermined angle θ (in this case, 90 degrees) between them. Thedirectivity of the antenna 2403 can be controlled by adjusting the angleθ through a hinge mechanism.

It should be further noted that the number of antenna elements is oneaccording to the present embodiment but it is not limited to thisembodiment and may be two or more. It should be also noted that thesubstrate consists of a single conductor but the body or the like of anautomobile may be used as the substrate.

(Embodiment 9)

FIG. 25 is a schematic diagram showing an example of an antenna deviceaccording to the ninth embodiment of the present invention. One antennaconsists of a group of antenna elements where a plurality of antennaelements are arranged in a predetermined area and served by a singlefeeding mechanism. As shown in FIG. 25(a), a plurality of antennaelements 2501, 2502, and 2503 are served by a single feeding mechanismto provide an antenna consisting of the group of antenna elements. Forexample, a broadband antenna which covers a desired bandwidth as a wholecan be implemented by covering a different bandwidth with each of theantenna elements. Particularly, in the arrangement of FIG. 25(a), theouter antenna element 2501 is necessarily longer than the inner antennaelement 2503 and it is easy to set the longer antenna element 2501 to alower tuning frequency and the shorter antenna element 2503 to a highertuning frequency, so that an antenna covering a broad band as a wholecan be implemented.

As shown in FIG. 25(b), a plurality of antenna elements may beseparately arranged while these elements have a common antenna plane.

If each of the antenna elements covers the same band, the efficiency ofthe antenna can be improved.

To provide isolation between the antenna elements, a distance betweenthem may be determined to keep them in predetermined isolation or anisolator or reflector may be connected to each of the antenna elements.

It should be noted that the number of antenna elements is two or threeaccording to the present embodiment but it is not limited to the presentembodiment and may be any number equal to or more than two.

(Embodiment 10)

FIG. 26 is a schematic diagram showing an example of an antenna deviceaccording to the tenth embodiment of the present invention. It differsfrom the ninth embodiment of the present invention in that as shown inFIG. 26(a), antenna elements 2601, 2602, and 2603 or antenna element2604, 2605, and 2606 are layered in a direction perpendicular to thereference plane. It should be noted that the antenna elements may bearranged so that they are all exactly overlaid on the surface ofprojection as shown in the left of the figure or so that they arepartially overlaid as shown in the right of the figure or so that theyare separate from each other. FIG. 26(b) is a partial broken viewshowing an application of the present embodiment, in which antennas 2611and 2612 are formed on a multilayer printed circuit board 2609 through aprinted-wiring technique and the antennas are arranged to be partiallyoverlaid on the horizontal plane. Both elements can be coupled in placeby running a conductor through a through-hole 2610.

(Embodiment 11)

FIG. 27 is a schematic diagram showing an example of an antenna deviceaccording to the eleventh embodiment of the present invention and FIG.27(a) shows an example of an antenna feeding section obtained by makinga plurality of antenna elements having a single antenna feeding means.As shown in FIG. 27(a), antenna elements 2701, 2702, and 2703 have taps2704, 2705, and 2706 formed in place thereon, respectively, to connectthem to a feeding terminal 2707. It should be noted that the directionfor tapping is identical for all the antenna elements but it may bearbitrarily determined for each of them.

FIG. 27(b) shows an antenna having a common electrode between the tap ofeach antenna element and a feeding terminal. As shown in the figure,taps 2704, 2705, and 2706 are formed in place on antenna elements 2701,2702, and 2703, respectively and a common electrode 2708 is providedbetween the taps and a feeding terminal 2707. This makes theconfiguration simple and in addition, a more compact antenna can beimplemented by placing the electrode 2708, for example, parallel to theoutermost antenna element 2701.

FIG. 28 shows an antenna with each antenna element tapped through areactance element. As shown in FIG. 28(a), antenna elements 2801, 2802,and 2803 may be separately connected to a feeding terminal 2807 throughreactance elements 2804, 2805, and 2806, respectively, or as shown inFIG. 28(b), a reactance element 2809 may be provided within a commonelectrode 2808 between a feeding terminal 2807 and taps. In the lattercase, a reactance element may be provided between the feeding terminaland a ground terminal as shown in FIG. 9 described above. By using aproper reactance element in this way, a desired impedance, band, andmaximum efficiency can be achieved. It should be noted that a variablereactance element may be used as such a reactance element foradjustment.

(Embodiment 12)

FIG. 29 is a schematic diagram showing an example of an antenna deviceaccording to the twelfth embodiment of the present invention. Accordingto the present embodiment, an antenna consists of a plurality of antennaelements arranged in a predetermined range in the proximity of aconductive substrate and served by a single feeding mechanism, a groundterminal of which is connected to the conductive substrate. As shown inFIG. 29, a plurality of antenna elements 2901, 2902, and 2903 are servedby a single feeding terminal 2907 provided on the opposite side of aconductive substrate 2909 to the antenna elements to provide an antennaconsisting of the group of antenna elements and a ground terminal 2908of the feeding section is connected to the conductive substrate 2909.This configuration can allow a compact high-gain antenna to be providedin a plane in the proximity of the conductive substrate.

(Embodiment 13)

FIG. 30 is a schematic diagram showing an example of an antenna deviceaccording to the thirteenth embodiment of the present invention.

As shown in FIG. 30(a), the tuning frequency is controlled by setting adistance between opposed portions 3001 and 3002 of an antenna elementnear its open terminals to a predetermined value to control the couplingbetween them.

The coupling between the opposed portions 3001 and 3002 of the antennaelement near its open terminals can be established by providing adielectric 3003 as shown in FIG. 30(b) or by connecting them through areactance element 3004 as shown in FIG. 30(c). For this purpose, thedielectric 3003 may be movably provided to control the coupling or thereactance element 3004 may be implemented with a variable reactance tocontrol the coupling.

It should be noted that the number of antenna elements is one accordingto the present embodiment but it is not limited to this embodiment andmay be two or more like the antenna shown in FIG. 25 described above.

(Embodiment 14)

FIG. 31 is a schematic diagram showing an example of an antenna deviceaccording to the fourteenth embodiment of the present invention.

As shown in FIG. 31(a), the tuning frequency is controlled by setting adistance between open-terminal portions 3101 and 3102 of an antennaelement and the neutral point 3103 or their opposed portions 3111 and3112 near the neutral point to a predetermined value.

The coupling between the open-terminal portions of the antenna elementand the neutral point or their opposed portions near the neutral pointcan be established, as shown in FIGS. 31(b) and (c), by providing adielectric 3104 or by connecting them through a reactance element 3105or 3106. For this purpose, like the thirteenth embodiment describedabove, the dielectric 3104 may be movably provided to control thecoupling or the reactance element 3101 or 3102 may be implemented with avariable reactance to control the coupling.

It should be noted that the number of antenna elements is one accordingto the present embodiment but it is not limited to this embodiment andmay be two or more like the antenna shown in FIG. 25 described above.

(Embodiment 15)

FIG. 32 is a schematic diagram showing an example of an antenna deviceaccording to the fifteenth embodiment of the present invention. In theantenna device according to the present embodiment, at least one linearconductor is connected to each end of a coil, a ground terminal ispulled out of the neutral point of the coil, and a tap is formed inplace on the linear conductor or the coil to provide a feeding terminalat the end of the tapping cable. As shown in FIG. 32(a), a coil 3203 hasa linear conductor 3201 or 3202 at each end of the coil, a groundterminal 3206 is pulled out of the neutral point of the coil 3203, and atap 3204 is formed in place on the linear conductor (in this case, 3202)to provide a feeding terminal 3205 at the end of the tapping cable. Asshown in FIG. 32(b), a tap 3204 may be formed in place on a coil 3203 toprovide a feeding terminal 3205.

This configuration can allow the tuning frequency of the antenna to beadjusted by controlling the number of turns of coil winding and inaddition, it can allow the implementation of a more compact andbroadband antenna.

FIG. 33 shows that an antenna device has a plurality of linearconductors connected to a coil. As shown in FIG. 33(a), a coil 3307 hasa plurality of linear conductors 3301, 3302, and 3303 or 3304, 3305, and3306 at each end of the coil, a ground terminal 3311 is pulled out ofthe neutral point 3310 of the coil 3307, and a tap 3308 is formed inplace on the linear conductors (in this case, 3304, 3305, and 3306) toprovide a feeding terminal 3309 at the end of the tapping cable. Asshown in FIG. 33(b), a tap 3312 may be formed in place on a coil 3307 toprovide a feeding terminal 3309. It should be noted that the threelinear conductors are provided on each side of the coil according to thepresent embodiment but it is not limited to this embodiment and may beany number equal to or more than two.

It should be also noted that the conductors used as antenna elements inthe present embodiment are all linear but the shape of each conductor isnot limited to this embodiment and any conductor may have at least onebend or curve or may be spiral.

(Embodiment 16)

FIG. 34 is a schematic diagram showing an example of an antenna deviceaccording to the sixteenth embodiment of the present invention. Theantenna device according to the present embodiment has one or two groupsof linear conductors and each group of them is connected to a feedingsection through a coil. As shown in FIG. 34, a group of linearconductors 3401, 3402, and 3403 and another group of linear conductors3404, 3405, and 3406 are connected to common electrodes 3407 and 3408,respectively, and these electrodes are connected to a feeding section3411 through coils 3409 and 3410, respectively. This configuration canallow the tuning frequency of the antenna to be adjusted by controllingthe number of turns of coil winding and in addition, it can allow theimplementation of a more compact and broadband antenna.

(Embodiment 17)

FIG. 35 is a schematic diagram showing the configuration of an exampleof an antenna device according to the seventeenth embodiment of thepresent invention. The antenna device according to the presentembodiment comprises a plurality of antennas consisting of a pluralityof antenna element groups and these antennas are provided within apredetermined range for diversity reception to select one of them whichcan achieve the optimum receiving state. For example, in FIG. 35, twoantennas 3501 and 3502 are switched by a diversity changeover switch3503 connected to a feeding section of each antenna to select one of theantennas which can achieve the optimum radio-wave propagation. It shouldbe noted that the number of antennas is not limited to two as describedfor the present embodiment but it may be three or more. It should bealso noted that the type of antennas is not limited to that shown inFIG. 35 but other types of antennas as described for the precedingembodiments or different types of antennas may be used.

In addition, selection of the optimum antenna from a plurality ofantennas may be accomplished by selecting one which can achieve themaximum receiver input or by selecting one which can achieve the minimumlevel of multipath disturbance.

It should be further noted that a feeding section for serving eachantenna element or each antenna consisting of a plurality of antennaelement groups according to the preceding embodiments 1 through 17described above may have a balance-to-unbalance transformer, a modeconverter, or an impedance converter connected to it.

(Embodiment 18)

FIG. 36 is a schematic diagram showing possible locations where anantenna device according to the eighteenth embodiment of the presentinvention is to be installed. In the description of the presentembodiment, it is assumed that the antenna is installed on an automobileand the antenna to be installed is as described for the precedingembodiments. As shown in FIG. 36, possible locations for installationinclude a rear spoiler 3601, a trunk lid rear panel 3602, a rear tray3603, a roof spoiler 3604, a roof box 3606, and a roof 3605 such as asunroof visor.

If an antenna is to be installed in a vertical position, for example, itmay be installed on the end 3703 of an automobile spoiler 3701 or 3702or the end 3703 of a sun visor as shown in FIG. 37(a) or on a pillarsection 3704 as shown in FIG. 37(b). Of course, installation locationsare not limited to them and the antenna may be installed on any otherlocations which are tilted to some extent with respect to any horizontalplane. Therefore, the reception of a desired polarized wave can be madevery easy by positioning the antenna at such locations.

As described above, each antenna device according to the presentinvention can be installed without any portion protruding from the bodyplane of an automobile because it can be located with its antenna planeparallel to and in the proximity of the body plane which is a conductivesubstrate and in addition, it can be installed even in a narrow spacebecause it takes up only a small area. Therefore, its appearance can beimproved with little wind soughing brought about around it and inaddition, some other problems such as a risk of its being stolen andlabors involved in removing it before car wash can be eliminated.

(Embodiment 19)

FIG. 38 is a schematic diagram showing an example of a mobilecommunication device with an antenna device according to the nineteenthembodiment of the present invention. As shown in FIG. 38, an antenna3801 according to any one of the preceding embodiments described aboveis installed on the ceiling of an automobile body 3805. In this case, ifthe antenna 3801 is located within a recess 3806 in the ceiling, anyportion of the antenna will not protrude from the outline of the body3805. As seen from the figure, the antenna 3801 is connected to acommunication device 3804 which is installed inside the body 3805 andconsists of an amplifier 3802 and a modem 3803.

(Embodiment 20)

FIG. 39 is a schematic diagram showing an example of a portabletelephone with an antenna device according to the twentieth embodimentof the present invention. FIG. 39(a) shows an example in which aconductive shielding case 3902 provided inside a resinous case 3901 of aportable telephone is used as a conductive substrate and an antenna 3903is located along the inner side of the case 3901 to be parallel to theshielding case 3902. FIG. 39(b) shows another example in which anantenna 3904 is located on the top surface outside a resinous case 3901of a portable telephone and a conductive substrate 3905 is provided onthe inner wall of the case 3901 opposite to the antenna 3904. In thelatter case, the top of a shielding case 3902 is too small to be used asa conductive substrate. The antennas used in FIGS. 39(a) and (b) arepreferably those having more bends or more turns of winding which caneasily allow the implementation of a compact antenna.

With these configurations, the directional gain on the conductivesubstrate side is very small from the side of the antenna and therefore,possible influence of electromagnetic waves on human body can be reducedwithout any degradation of antenna efficiency if the antenna device isused with the conductive substrate side turned to the user.

It should be noted that the antenna device according to the eighteenthembodiment described above is installed on an automobile but it may beinstalled on other vehicles such as an airplane or ship. Alternatively,it may be installed not only on such vehicles but also on the roadbed,shoulder, tollgate, or tunnel wall of any expressway or highway, or onthe wall or window of any building.

It should be also noted that the antenna device according to thenineteenth embodiment described above is used with a mobilecommunication device but it may be used with any other device whichreceives or transmits radio waves, for example, a television set, aradiocassette player, or a radio set.

It should be further noted that the antenna device according to thetwentieth embodiment is implemented in a portable telephone but it mayapply to other portable radio sets, for example, a PHS device, a pager,or a navigation system.

(Embodiment 21)

FIG. 42 is a schematic diagram showing the configuration of an antennadevice according to the twenty-first embodiment of the presentinvention. Namely, FIG. 42(a) shows a monopole-type broadband antennawhich comprises a main antenna element 4202 having an end connected to aground 4204, an antenna element 4201 located in the proximity of themain antenna element 4202 and having a length longer than the antennaelement 4202 and no end connected to a ground, and an antenna element4203 having a length shorter than the antenna element 4202 and no endconnected to a ground. The main antenna element 4202 is provided with atap which is connected to a feeding point 4206 through a reactanceelement 4205 for impedance adjustment. FIG. 42(b) shows another antennadevice which is obtained by forming on a printed circuit board 4207antenna elements 4201, 4202, and 4203 of the antenna device of FIG.42(a) described above through a printed-wiring technique.

FIG. 43 is a schematic diagram showing a dipole-type antenna deviceaccording to the embodiment described above. Namely, FIG. 43(a) shows adipole-type broadband antenna which comprises a main antenna element4302 having the center connected to a ground 4304, an antenna element4301 located in the proximity of the main antenna element 4302 andhaving a length longer than the antenna element 4302 and no portionconnected to a ground, and an antenna element 4303 having a lengthshorter than the antenna element 4302 and no portion connected to aground. The main antenna element 4302 is provided with a tap which isconnected to a feeding point 4306 through a reactance element 4305 forimpedance adjustment. FIG. 43(b) shows another antenna device which isobtained by forming on a printed circuit board 4307 antenna elements4301, 4302, and 4303 of the antenna device of FIG. 43(a) described abovethrough a printed-wiring technique.

These configurations can implement a broadband and high-gain antennadevice which is very simple and easy to adjust.

It should be noted that a shorter antenna element and a longer antennaelement are located in the proximity of a main antenna element accordingto the present embodiment described above but two or more antennaelements may be located on each side of the main antenna.

(Embodiment 22)

FIG. 44 is a schematic diagram showing the configuration of an antennadevice according to the twenty-second embodiment of the presentinvention. Namely, FIG. 44(a) shows an antenna device similar to thoseshown in FIG. 10 or other figures described above, in which a conductivesubstrate is located in the proximity of antenna elements and theantenna device according to the present embodiment differs from thosedevices in that a conductive substrate 4404 located in the proximity ofantenna elements 4401, 4402, and 4403 is almost equal in size to orsmaller than the outermost antenna element 4401. Such a configurationcan improve the gain for horizontally polarized waves as compared withthe case where a conductive substrate is larger than an antenna element.

FIG. 44(b) shows that the antenna device of FIG. 44(a) described aboveis located within a recess in a vehicle body, the case of acommunication device, the wall of a house, or any other device case andthat an antenna ground (conductive substrate) 4404 is not connected to aground for such a case. This configuration can provide a higher gain forboth horizontally and vertically polarized waves. The directional gaincharacteristics of this antenna device are shown in FIG. 94 forvertically polarized waves. As seen from the figure, when the distance(that is, separation) between an antenna ground and a case ground is (a)10 mm, (b) 30 mm, (c) 80 mm, or (d) 150 mm, the shorter distance canprovide the higher gain. Namely, when the antenna ground is closer tothe case ground, the better performance can be obtained. It should benoted that in the example, the antenna ground 4404 is located within arecess in a vehicle body, the case of a communication device, the wallof a house, or any other device case to prevent the antenna from poppingout of the outer case but the antenna ground may be located in theproximity of the flat plane of the case ground at a distance. Even inthe latter case, the antenna can provide the same effect as the formerand it falls within the scope of the present invention.

It should be also noted that an antenna element of balanced type is usedaccording to the present embodiment but an antenna element of unbalancedtype may result in similar effects.

(Embodiment 23)

FIG. 45 is a schematic diagram showing the configuration of an antennadevice according to the twenty-third embodiment of the presentinvention. The present embodiment shows how far adjacent to a conductivesubstrate an antenna element is to be located and FIG. 45(a) is anexample where a single antenna element is located. Namely, the distanceh between an antenna element 4501 (to speak properly, an antennagrounding connection) and a conductive substrate 4502 is set to a valuewithin 0.01 to 0.25 times as large as a wavelength λ for the resonancefrequency f of the antenna (that is, 0.01λ to 0.25λ). This configurationcan implement a high-gain antenna which is very easy to adjust.

FIG. 45(b) is another example where four antenna elements 4503, 4504,4505, and 4506 are located at different distances from a conductivesubstrate 4507, respectively. As shown in FIG. 45(b), when the antennaelements have different lengths, the shorter element can have the higherresonance frequency and the shorter wavelength. Therefore, the distanceh1 for the shortest antenna element 4506 may be set to the smallestvalue, the distance h2 for the longest antenna element 4503 may be setto the largest value, the distances for the medium antenna elements 4504and 4505 may be set to values depending on the wavelengths at theirresonance frequencies, respectively. Then the distance between each ofthe antenna elements 4503, 4504, 4505, and 4506 and the conductivesubstrate 4507 must satisfy the condition that it falls within the rangeof 0.01 to 0.25 times as large as a wavelength λ for the resonancefrequency f of each antenna element (that is, 0.01λ to 0.25λ).

(Embodiment 24)

FIG. 46 is a schematic diagram showing the configuration of an antennadevice according to the twenty-fourth embodiment of the presentinvention. In the present embodiment, a high-permittivity material isprovided between an antenna element 4601 and a conductive substrate4602. Therefore, this configuration can apply to any other embodimentwhere a conductive substrate is located in the proximity of an antennaelement. It should be also noted that the distance between the antennaelement and the conductive substrate can be reduced equivalently byproviding such a high-permittivity material between them.

(Embodiment 25)

FIG. 47 is a schematic diagram showing a possible automobile applicationof an antenna device according to the twenty-fifth embodiment of thepresent invention. Namely, any one of the antenna devices according tothe preceding embodiments described above is installed at five locationsin total, that is, one on each of the four pillars 4701 of the front,back, right and left of the automobile, and one on the roof, to providea diversity configuration of these flat antennas. This configuration canoffer a good capability of receiving and transmitting both horizontallyand vertically polarized waves. It should be noted that the antennadevice is installed at five locations according to the presentembodiment but it may be installed at more or less locations.

(Embodiment 26)

FIG. 48 is a schematic diagram showing possible locations where anantenna device according to the twenty-sixth embodiment of the presentinvention is to be installed for automobile applications. Namely, anyone of the antenna devices according to the preceding embodimentsdescribed above is installed at any one or more locations on the roofpanel, hood, pillars, side faces, bumpers, wheels, floor, or othersurface portions of an automobile body 4801. In FIG. 48, an antenna 4802is installed at a location where the antenna plane is almost in ahorizontal position, an antenna 4803 is installed at a location wherethe antenna plane is in a tilted position, and an antenna 4804 isinstalled at a location where the antenna plane is almost in a verticalposition. It should be noted that this figure shows possible locationsfor antenna installation by way of example and all the locations shownare not provided with antennas. Of course, it should be also noted thatan antenna may be installed at any location other than those shown. Itshould be further noted that the automobile type is not limited to sucha passenger car as shown and an antenna according to the presentinvention may be installed on a bus, truck, or any other type ofautomobile.

In addition, since an antenna 4805 is installed at a location where theantenna plane is in a horizontal position, and specifically, on the back(undersurface) of the floor with its directivity facing the roadbed, itis suitable for communication with a wave source installed on the road(or embedded therein) which is to be used for communication or detectionof vehicle positions.

Generally, airwaves for TV or FM broadcasting mainly consist ofhorizontally polarized waves, while waves for portable telephone orradio communication mainly consist of vertically polarized waves.Whether an antenna is suitable for horizontally polarized waves orvertically polarized waves depends on the direction of its installation.As shown in FIG. 49(a), an antenna 4902 which is installed parallel to aconductive substrate 4901, that is, a vertical surface portion of anautomobile body 4801 and comprises three antenna elements of unbalancedtype with their grounded ends connected together is effective forhorizontally polarized waves, since its sensitivity to horizontallypolarized waves can be raised because of the horizontal electric fieldas shown in the right of the figure. This can be accomplished byinstalling an antenna 4804 as shown in FIG. 48. On the other hand, anantenna 4802 which is installed parallel to a horizontal surface portionof the automobile body 4801 is effective for vertically polarized waves,since its sensitivity to vertically polarized waves can be raisedbecause of the vertical electric field. In addition, an antenna 4803which is installed in a tilted position can be used regardless of thedirection of polarization, since its sensitivity is balanced betweenhorizontally and vertically polarized waves depending on the degree oftilt. FIG. 49(b) shows an example of antenna of balanced type, which iseffective for horizontally polarized waves in a similar manner to thatdescribed above.

(Embodiment 27)

FIG. 50 is a schematic diagram showing the configuration of an antennadevice according to the twenty-seventh embodiment of the presentinvention. The antenna device according to the present embodimentdiffers from the antenna devices according to the preceding embodimentsdescribed above in that it receives or transmits waves from the side ofits conductive substrate rather than from the side of its antennaelements. As shown in FIG. 50(a), an antenna 5002 of three antennaelements is installed parallel to a conductive substrate 5001 at adistance and a grounded end of the antenna 5002 is connected to theconductive substrate 5001, which faces toward the outside. This antennahas symmetrical directional characteristics on the upper region of theconductive substrate 5001 corresponding to the area covered by theantenna 5002 (on the opposite side to the antenna 5002) and on the lowerregion thereof as shown in FIG. 50(b). Therefore, even if the antenna5002 and the conductive substrate 5001 are located inversely, it canachieve the same effect as those of the antennas according to thepreceding embodiments described above. In addition, even if a conductivesubstrate 5003 is formed as a sealed case as shown in FIG. 50(c), anantenna 5002 inside the conductive substrate 5003 can have similarcharacteristics and communicate with the outside through the conductivesubstrate 5003 when it is fed.

FIG. 51 shows an example of an antenna device of balanced type which canachieve the same effect as those described above, while FIG. 50 shows anantenna device of unbalanced type.

FIG. 52 is a schematic diagram showing possible locations where theantenna device according to the present embodiment is to be installedfor automobile applications similar to those of FIG. 48. In FIG. 52,like in FIG. 48, an antenna 5202 is installed at a location where theantenna plane is almost in a horizontal position, an antenna 5203 isinstalled at a location where the antenna plane is in a tilted position,and an antenna 5204 is installed at a location where the antenna planeis almost in a vertical position. In addition, since an antenna 5205 isinstalled at a location where the antenna plane is in a horizontalposition, and specifically, on the inner surface of the floor, it issuitable for communication with a wave source installed on the road in asimilar manner to that of FIG. 48. Although these antennas shown are allinstalled inside an automobile body 5201, they can achieve the sameperformance as that for the antennas installed on the outer surface ofthe automobile body for the reasons described above and in addition,they are very advantageous in appearance, damages, or risk of beingstolen because they are not exposed to the outside of the body.Moreover, as shown in FIG. 52, the antenna device according to thepresent embodiment may be installed on a rearview mirror, in-car sunvisor, number plate, or any other location where it cannot be otherwiseinstalled on the outer surface, by embedding it within the inside spaceof such a component.

FIG. 53 is a schematic diagram showing a possible application to aportable telephone of the antenna according to the present embodiment,in which an antenna 5302 is installed inside a conductive grounded case5301 with an antenna ground connected to the the conductive groundedcase 5301. This configuration can allow the antenna to be used in asimilar manner to the case where the antenna is installed outside thegrounded case 5301 and it can make the antenna very advantageous inhandling because the antenna is not exposed to the outside. It should benoted that the antenna is used with a portable telephone according tothe present embodiment but it can also apply to a TV, PHS, or otherradio set.

FIG. 54 is a schematic diagram showing a possible application to anordinary house of the antenna according to the present embodiment.Namely, an antenna 5402 is installed inside a conductive door of a house5401, an antenna 5403 is installed inside a conductive window (forexample, storm window), an antenna 5404 is installed inside a conductivewall, and an antenna 5405 is installed inside a conductive roof.Therefore, when an antenna is installed inside a conductive structure ofthe house 5401 in this way, the antenna can be protected againstweather-induced damage or degradation with an elongated service lifebecause it is not exposed to the outside.

It should be further noted that even if a house consists ofnonconductive structures, such an antenna can be installed at anylocation by attaching a conductor to the outer surface thereof.

(Embodiment 28)

FIG. 55 is a schematic diagram showing the configuration of an antennaaccording to the twenty-eighth embodiment of the present invention. Inthe present embodiment, a conductive substrate 5501 and an antenna 5502installed parallel to and in the proximity of the substrate can beturned (or rotated) together on the axis as shown by a dash-dot line. Asshown in FIG. 55(a), when an antenna 5502 is in a vertical position, theelectric field is horizontal as shown in the right of the figure and itssensitivity for horizontally polarized waves becomes high. As shown inFIG. 55(b), when the antenna 5502 is in a horizontal position, theelectric field is in turn vertical as shown in the right of the figureand its sensitivity for vertically polarized waves becomes high andtherefore, the antenna can be directed in the optimum position dependingon the state of polarized waves. Of course, it may be directed in atilted position. The directional gain characteristics of the antennainstalled as shown in FIG. 55(a) are shown in FIG. 95 and thedirectional gain characteristics of the antenna installed as shown inFIG. 55(b) are shown in FIG. 96. As apparent from these figures, anantenna in a vertical position can exhibit a high sensitivity tohorizontally polarized waves, while an antenna in a horizontal positioncan exhibit a high sensitivity to vertically polarized waves.

It should be noted that the conductive substrate 5501 and the antenna5502 can be turned manually by operating the handle by hand orautomatically by using a motor or any other drive.

FIG. 56(a) is a schematic diagram showing the configuration of anotherantenna device which can achieve the same effects as those describedabove without turning the antenna. Namely, a ferroelectric 5603 islocated between a conductive substrate 5601 and an antenna 5602 so thatit can sandwich the antenna 5602. As shown in the right of FIG. 56(b),this configuration can allow the electric field between a conductivesubstrate 5604 and an antenna 5605 to be extended in a horizontaldirection through a ferroelectric 5606, so that the vertical componentis decreased and the horizontal component is increased as compared withthe case where no ferroelectric is used as shown in the left of thefigure. The antenna can be set for vertically polarized waves orhorizontally polarized waves depending on whether a ferroelectric isused or not. It should be noted that if the antenna is installed in avertical position, such a ferroelectric will have an inverse effect onthe antenna. It should be further noted that the ferroelectric 5603 maybe installed during the manufacture or later and it may be made easilyremovable by providing grooves for this purpose.

(Embodiment 29)

FIG. 57 is a schematic diagram showing the configuration of an exampleof an antenna device according to the twenty-ninth embodiment of thepresent invention. Although the antenna devices according to thepreceding embodiments described above use bent elements which can beinstalled even in a narrow space, an antenna device according to thepresent embodiment uses a linear element which can be installed on anelongate component of an automobile or an element shaped to a component.

FIG. 57(a) shows that a linear antenna 5702 with three elements islocated in the proximity of the surface of an elongate plate likeconductive substrate 5701. FIG. 57(b) shows that a linear antenna 5704with three elements is located in the proximity of the surface of acylindrical conductive substrate 5703 so that each element is at thesame distance from the conductive substrate 5703. FIG. 57(c) shows thata linear antenna 5706 with three elements is located in the proximity ofthe surface of a quadrangular-prism conductive substrate 5705 so thateach element is at the same distance from the conductive substrate 5705.

FIG. 58 shows variations of the present embodiment shown in FIG. 57, inwhich elements are curved or bent in accordance with a curved or bentconductive substrate. FIG. 58(a) shows that an antenna 5802 with threecurved elements is located in the proximity of the surface of a curvedcylindrical conductive substrate 5801 so that each element is at thesame distance from the conductive substrate 5801. FIG. 58(b) shows thatan antenna 5804 with three bent elements is located in the proximity ofthe surface of a bent quadrangular-prism conductive substrate 5803 sothat each element is at the same distance from the conductive substrate5803. FIG. 58(c) shows that an antenna 5806 with three bent elements islocated in the proximity of the surface of a bent plate like conductivesubstrate 5805.

In addition, FIG. 59(a) shows that an antenna 5902 is located along thesurface of a cylindrical conductive substrate 5901 and FIG. 59(b) showsthat an antenna 5904 is located along the surface of a sphericalconductive substrate 5903.

It should be noted that the antenna according to the present embodimentis located outside a component which constitutes a conductive substratebut it is not limited to this example and it may be located inside aplate like component or on the inner surface of a cylindrical component.

FIGS. 63 and 65 show applications of the antenna device according to thepresent embodiment. FIG. 63 shows that an antenna 6302 is installed onthe surface of an elongate roof rail 6303 on the roof of an automobilebody 6301 and FIG. 65 shows that an antenna 6502 is installed inside anelongate roof rail 6503 on the roof of an automobile body 6501.

Moreover, FIGS. 64 and 66 show other applications of the antenna deviceaccording to the present embodiment. FIG. 64 shows that an antenna 6403is installed on the surface of an elongate roof box 6402 on the roof ofan automobile body 6401 and FIG. 66 shows that an antenna 6603 isinstalled inside an elongate roof box 6602 on the roof of an automobilebody 6601.

(Embodiment 30)

FIGS. 60(a) and 60(b) are schematic diagrams showing the configurationof an example of an antenna device according to the thirtieth embodimentof the present invention. The antenna device according to the presentembodiment comprises an antenna 6002 with three longer elements and anantenna 6003 with three shorter elements with respect to an groundedpoint connected to a conductive substrate 6001 and feeding points A 6005and B 6004 are provided for these antennas 6002 and 6003, respectively.As shown in FIG. 60(c), the shorter antenna 6003 is tuned to the A bandof relatively higher frequencies and the longer antenna 6002 is tuned tothe B band of relatively lower frequencies, and thus, such a singleantenna device can accommodate two tuning bands. It should be noted thatthe feeding points A 6005 and B 6004 may be connected to each other.

FIGS. 61(a) and 61(b) are schematic diagrams showing another example ofthe antenna of unbalanced type having two tuning bands. This antenna isa four-element antenna having an end connected to a conductive substrate6101 and located in the proximity of the conductive substrate 6101 andin addition, an antenna 6102 with two relatively longer elements isprovided with a feeding point B 6104 and an antenna 6103 with tworelatively shorter elements is provided with a feeding point A 6105. Asshown in FIG. 61(c), this configuration can accommodate two tuningbands, that is, the A band of relatively higher frequencies and the Bband of relatively lower frequencies in a similar manner to that of thepreceding example. It should be also noted that the feeding points A6005 and B 6004 may be connected to each other.

FIGS. 62(a) and 62(b) are schematic diagrams showing still anotherexample of the antenna of balanced type having two tuning bands. Thisantenna is a four-element antenna having the midpoint connected to aconductive substrate 6201 and located in the proximity of the conductivesubstrate 6201 and in addition, an antenna 6202 with two relativelylonger elements is provided with a feeding point B 6204 and an antenna6203 with two relatively shorter elements is provided with a feedingpoint A 6205. As shown in FIG. 62(c), this configuration can accommodatetwo tuning bands, that is, the A band of relatively higher frequenciesand the B band of relatively lower frequencies in a similar manner tothat of the preceding examples. It should be also noted that the feedingpoints A 6005 and B 6004 may be connected to each other.

Therefore, the present embodiment can provide an advanced antenna devicewhich requires a minimum space for installation and which is capable ofaccommodating a plurality of tuning bands, and thus, such an antenna canbe applicable in a narrow space such as an automobile or a portabletelephone.

It should be noted that the present embodiment assumes two tuning bandsbut it may accommodate three or more bands. The latter case can beaccomplished by providing a plurality of antennas each of which has anelement length corresponding to each tuning band and providing a feedingpoint for each antenna.

(Embodiment 31)

FIG. 67 is a schematic diagram showing the configuration of an exampleof an antenna device according to the thirty-first embodiment of thepresent invention. In the antenna device according to the presentembodiment, a coil 6703 is provided in place on a three-edge antennaelement 6701 located in the proximity of a conductive substrate 6702 andan end of the antenna element 6701 is connected to the conductivesubstrate 6702. In addition, a feeding section 6704 is provided on theantenna element 6701 between the coil 6703 and the conductive substrate6702. This configuration can allow an electric current to concentrate inthe coil and thus the antenna device can be reduced in size with thegain unchanged. For example, if the antenna element consists of a stripline, the area for the antenna can be reduced to a quarter. Moreover,its bandwidth can be narrowed with a sharp band characteristic.

FIG. 68 shows that two antenna elements having the configuration of FIG.67 are connected in parallel for band synthesis. Namely, two antennaelements 6801 a and 6801 b having different bands (lengths) and coils6803 a and 6803 b provided in place on the elements, respectively, arelocated in parallel and an end of each element is connected to aconductive substrate 6802. In addition, the antenna elements 6801 a and6801 b are connected to a common feeding section 6804 through reactanceelements 6805 a and 6805 b, respectively. This configuration cansynthesize the bands of the two antenna elements and thus, a broadbandantenna device with the same effects as those described above can beimplemented.

(Embodiment 32)

FIG. 69 is a schematic diagram showing the configuration of an exampleof an antenna device according to the thirty-second embodiment of thepresent invention. In the antenna device according to the presentembodiment, a coil 6903 is provided between an end of a three-edgeantenna element 6901 located in the proximity of a conductive substrate6902 and the conductive substrate 6902 and the other end of the coil6903 is connected to the conductive substrate 6902 for grounding. Inaddition, a feeding section 6904 is provided in place on the antennaelement 6901. This configuration can allow an electric current toconcentrate in the coil in a similar manner to that for thethirty-second embodiment described above and thus the antenna device canbe reduced in size with the gain unchanged.

FIG. 70 shows that two antenna elements having the configuration of FIG.69 are connected in parallel for band synthesis. Namely, two antennaelements 7001 a and 7001 b having different bands (lengths) are locatedin parallel with an end connected to an end of a common coil 7003 andthe other end of the coil 7003 is connected to a conductive substrate7002. In addition, the antenna elements 7001 a and 7001 b are connectedto a common feeding section 7004 through reactance elements 7005 a and7005 b, respectively. This configuration can synthesize the bands of thetwo antenna elements and thus, a broadband antenna device with the sameeffects as those described above can be implemented. It should be notedthat the single coil which is shared by the two antenna elements cancontribute to a simple configuration.

(Embodiment 33)

FIG. 71 is a schematic diagram showing an example of an antenna deviceaccording to the thirty-third embodiment of the present invention. Thepresent embodiment differs from the thirty-second embodiment describedabove in that as shown in FIG. 71, an insulator 7105 is provided on aconductive substrate 7102 and an antenna element 7101 and a coil 7103are connected on the insulator 7105. This configuration can allow easyinstallation of a coil 7103, which is useful for its implementation, andthus the coil can be stably installed. FIG. 72 shows the configurationof two antenna elements 7201 a and 7201 b arranged for band synthesis.As shown in the figure, although the connection between a coil 7203 andthe antenna elements becomes more complex because of the more antennaelements as compared with the case of FIG. 71, a connection pointprovided on an insulator 7205 on a conductive substrate 7202 can makethe connection between the antenna elements and the coil much easier.

(Embodiment 34)

FIG. 73 is a schematic diagram showing an example of an antenna deviceaccording to the thirty-fourth embodiment of the present invention. Inthe antenna device according to the present embodiment, two coilsections are separately provided and two insulators 7305 a and 7305 bare provided on a conductive substrate 7302 to connect antenna elementsand coils. Namely, an end of a three-edge antenna element 7301 providedin the proximity of a conductive substrate 7302 and an end of a coil7303 a are connected together on an insulator 7305, the other end of thecoil 7303 a and an end of another coil 7303 b and a feeding section 7304are connected together on another insulator 7305 b, and the other end ofthe coil 7303 b is connected to the conductive substrate 7302 forgrounding. FIG. 74 shows an antenna device having two antenna elements7401 a and 7401 b arranged for band synthesis and the antenna elements,coils, and a feeding section are connected in a similar manner to thatshown in FIG. 73.

These configurations can allow easy connection to other circuitcomponents because the feeding terminal is provided on a circuit board.

(Embodiment 35)

FIG. 75 is a schematic diagram showing the configuration of an exampleof an antenna according to the thirty-fifth embodiment of the presentinvention. In the antenna device according to the present embodiment, azigzag pattern 7503 is inserted in an antenna element 7501 in place ofthe coil for the configuration of FIG. 67. Although the configurationhaving a coil can three-dimensionally extend, the configuration withthis pattern 7503 can be formed on the same plane as the antenna element7501 and fabricated through a printed-wiring technique. FIG. 76 shows anantenna device having two antenna elements 7601 a and 7601 b arrangedfor band synthesis and zigzag patterns 7603 a and 7603 b are inserted inantenna elements 7601 a and 7601 b, respectively. It should be notedthat the zigzag patterns may be sawtoothed ones as shown in FIG. 78(c).

(Embodiment 36)

FIG. 77 is a schematic diagram showing the configuration of an exampleof an antenna according to the thirty-sixth embodiment of the presentinvention. In the antenna device according to the present embodiment,the whole antenna element 7701 located in the proximity of a conductivesubstrate 7702 is formed in a zigzag pattern and an end of the antennaelement 7701 is connected to an end of a coil 7703 which is grounded atthe other end. In addition, a feeding section 7704 is provided in placeon the zigzag antenna element. This configuration can allow the antennadevice to be further reduced in size, for example, to ⅙ or ⅛, althoughpossible losses may be increased. It should be noted that the antennaelement may be formed in other patterns, for example, those shown inFIGS. 78(b) and (c). The pattern shown in FIG. 78(b) is athree-dimensional coil.

(Embodiment 37)

FIG. 79 is a schematic diagram showing the configuration of an exampleof an antenna according to the thirty-seventh embodiment of the presentinvention. In the antenna device according to the present embodiment, aninsulator 7904 is provided on a conductive substrate 7902 and a lead7905 from an antenna element 7901 and a feeding section 7903 areconnected together on the insulator 7904. This configuration can alloweasy connection with other circuit components because the feedingsection 7903 is provided on a circuit board.

FIG. 80 shows that a through-hole 8005 is formed in a conductivesubstrate 8002 to provide an insulator 8004 on the opposite side of theconductive substrate 8002 to an antenna element 8001. A lead 8006 fromthe antenna element 8001 passes through the through-hole 8005 and theinsulator 8004 and connects to a feeding section 8003 on the insulator8004. This configuration can make it much easier than that of FIG. 79described above to connect other circuit components to the feedingsection 8003 because such circuit components can be connected on theback of the conductive substrate 8002.

FIG. 81 shows that in addition to the configuration of FIG. 80 describedabove, another conductive plate is provided on the back of a conductivesubstrate (on the opposite side to an antenna element) to mount variouscircuit components thereon. Namely, a through-hole 8104 is formed inboth a conductive substrate 8102 and a conductive plate 8105 to run alead 8111 from an antenna element 8101 therethrough and an insulator8103 is provided on the conductive plate 8105 over the through-hole8104. In addition, a required number of insulators 8106 are provided onthe conductive plate 8105 to connect various circuit components. Thelead 8111 passes through the through-hole 8104 to the insulator 8103 andcircuit components 8107 to 8110 are connected on the insulators 8103 and8106.

This configuration can allow location of the circuit in the proximity ofthe antenna and easy shielding between the antenna and the circuitthrough the conductive plate, and thus, it can facilitate implementing acompact device.

FIG. 82 shows still another example of the antenna in which circuitcomponents are located on the same side as an antenna element. Namely,an insulator 8203 to connect a lead 8205 from an antenna element 8201and a required number of insulators 8206 to connect various circuitcomponents are provided on a conductive substrate 8202. In addition, aconductive shielding case 8204 is provided on the conductive substrate8202 to shield the circuit components on the conductive substrate 8202from the antenna element 8201 and a through-hole 8207 is formed forrunning the lead 8205 therethrough. The lead 8205 passes through thethrough-hole 8207 to connect to the insulator 8203 and circuitcomponents 8208 to 8210 are connected on the insulators 8203 and 8206.An end of the antenna element 8201 is connected to the shielding case8204 for grounding.

This configuration can allow the whole circuit to be held between theantenna element and the conductive substrate and to be shielded by theshielding case, and thus, it can facilitate implementing a more compactdevice than the configuration of FIG. 81 described above.

(Embodiment 38)

FIG. 83 is a schematic diagram showing the configuration of an exampleof an antenna according to the thirty-eighth embodiment of the presentinvention. In the antenna device according to the present embodiment, anantenna element 8301 is formed on one side of an insulation plate 8305and one end 8307 of the antenna element 8301 passes through theinsulation plate 8305. A lead 8303 from a point in the antenna element8301 also passes through the insulation plate 8305 and another lead 8306formed on the opposite side of the insulation plate 8305 and parallel tothe antenna element 8305 is connected to the lead 8303 for connecting afeeding section 8304 to the lead 8306. It should be noted that thefeeding section 8304 is provided in the proximity of the end 8307 of theantenna element 8301. In addition, the insulation plate 8305 is locatedparallel to a conductive substrate 8302, to which the end 8307 of theantenna element 8301 is connected.

This configuration can facilitate connecting coaxial cables because thegrounded end of the antenna element is close to the feeding section.

(Embodiment 39)

FIG. 84 is a schematic diagram showing the configuration of an exampleof an antenna according to the thirty-ninth embodiment of the presentinvention. In the antenna device according to the present embodiment, aconductive substrate 8404 is provided on another broader conductivesubstrate 8402 through an insulation plate 8405 and an antenna element8401 is located in the proximity of the conductive substrate 8404. Itshould be noted that an end of the antenna element 8401 is connected tothe conductive substrate 8404 for grounding. It should be preferablethat the conductive substrate 8404 is equal to the antenna element 8401in size. Specifically, the conductive substrate 8402 may be the body ofan automobile or carriage, the metal case for a receiver orcommunication device, or any metal structure of a house and it may beinstalled inside or outside the room or compartment.

This configuration can achieve a nearly horizontal elevation angle withthe maximum gain and thus, it will be suitable for receivingcommunication waves (vertically polarized waves) which come from alateral direction.

It should be noted that any of the antenna devices according to thethirty-first through thirty-ninth embodiments can be installed at suchlocations as shown in FIGS. 36, 47, 48, 52, 53, and 54 to operateproperly.

It should be also noted that one or two antenna elements are used in anyof the antenna devices according to the thirty-first throughthirty-ninth embodiments but of course, three or more antenna elementsmay be used.

It should be further noted that antenna elements used in any of theantenna devices according to the thirty-first through thirty-ninthembodiments are in a three-edge shape but they may be in a loop or anyother shape.

It should be further noted that insulators used to provide connectionpoints according to the thirty-seventh through thirty-ninth embodimentsmay apply to any other antenna devices according to the precedingembodiments described above.

Next, the fortieth through forty-eighth embodiments of the presentinvention will be descried below with reference to the drawings.

The principle of the embodiments will be first described below. Asexplained in the section “BACKGROUND ART” above, when a conventionalantenna is located in the proximity of a conductive substrate, theantenna performance such as a directional gain may be affected by anautomobile body which constitutes a conductive substrate, like in amonopole antenna. According to the present invention, a high-selectivitynondirectional antenna with an improved directional gain can beimplemented by combining a cylindrical antenna and a planar antenna orcombining planar antennas to take advantage of the influences of aconductive substrate on the antenna.

(Embodiment 40)

FIG. 97 is a schematic diagram showing the configuration of an antennadevice according to the fortieth embodiment of the present invention andincludes its side and plan views. Namely, in FIG. 97, a cylindricalmonopole antenna 152 is located in the proximity of a conductivesubstrate 151 at a predetermined angle, and near an end of the monopoleantenna 152 where a feeding section 153 is provided, an antenna element154 with two bends is located with the antenna plane parallel to theconductive substrate 151. An end of the antenna element 154 farther fromthe monopole antenna 152 is connected to the conductive substrate 151and a feeding section 155 of the antenna element 154 is providedindependently of the feeding section 153 of the monopole antenna 152.

As shown in FIG. 97, the conductive substrate 151 is provided for themonopole antenna and it is also used as a substrate for the antennaelement 154 which is a planar antenna. Although the monopole antenna 152is applicable to both vertically and horizontally polarized waves, itsgain is a little lower. On the other hand, the antenna element 154 whichis a planar antenna has a sufficient capability of correctly receivingvertically polarized waves. Therefore, an antenna device intended forhorizontally polarized waves which has also a sufficient capability ofcorrectly receiving vertically polarized waves can be implemented byconnecting an automatic diversity changeover switch between the feedingsections 153 and 155 for the antennas to select which antenna canachieve the maximum gain depending on the state of received waves.

FIG. 98 shows that the planar antenna in the antenna device having theconfiguration described above consists of two antenna elements 254 and255 of different wavelengths and these antenna elements 254 and 255 areconnected to a single feeding section 258 through reactances 256 and257. This configuration can allow the implementation of a broadbandantenna and such an antenna can achieve a higher gain by using twoantenna elements of the same wavelength.

(Embodiment 41)

FIG. 99 is a schematic diagram showing the configuration of an antennadevice according to the forty-first embodiment of the present inventionand includes its side and plan views. Namely, in FIG. 99, a monopoleantenna 352 is located in the proximity of a conductive substrate 351 ata predetermined angle, and near an end of the monopole antenna 352 wherea feeding section 353 is provided, an antenna element 356 with two bendsis located with the antenna plane parallel to the conductive substrate351. An end of the antenna element 356 farther from the monopole antenna352 is connected to the conductive substrate 351 and a feeding section357 of the antenna element 356 and a feeding section 353 of the monopoleantenna 352 are connected to a single feeding section 355 through amixer 354.

According to the present embodiment, an antenna device intended forhorizontally polarized waves which has also a sufficient capability ofcorrectly receiving vertically polarized waves can be implemented byconnecting the monopole antenna 352 which can achieve satisfactory gainsfor both vertically and horizontally polarized waves and the antennaelement 356 which especially has a sufficient capability of correctlyreceiving vertically polarized waves.

FIG. 100 shows that the planar antenna in the antenna device having theconfiguration described above consists of two antenna elements 456 and457 of different wavelengths and these antenna elements 456 and 457 areconnected to a single feeding section through reactances 458 and 459.This configuration can allow the implementation of a broadband antennaand such an antenna can achieve a higher gain by using two antennaelements of the same wavelength.

(Embodiment 42)

FIG. 101 is a schematic diagram showing the configuration of an antennadevice according to the forty-second embodiment of the present inventionand includes its side and plan views. Namely, in FIG. 101, a monopoleantenna 552 is located in the proximity of a conductive substrate 551 ata predetermined angle, and near an end of the monopole antenna 552 wherea feeding section 553 is provided, an antenna element 554 with two bendsis located with the antenna plane parallel to the conductive substrate551. An end of the antenna element 554 closer to the monopole antenna552 is connected to the conductive substrate 551 and a feeding section555 of the antenna element 554 is provided independently of the feedingsection 553 of the monopole antenna 552.

According to the embodiment of FIG. 101, the grounded end of the antennaelement 554 has a smaller amount of electric field and interferencebetween antennas can be reduced by locating the grounded portion closerto the monopole antenna 552.

FIG. 102 shows that the planar antenna in the antenna device having theconfiguration described above consists of two antenna elements 654 and655 of different wavelengths and these antenna elements 654 and 655 areconnected to a single feeding section 658 through reactances 656 and657. This configuration can allow the implementation of a broadbandantenna and such an antenna can achieve a higher gain by using twoantenna elements of the same wavelength.

(Embodiment 43)

FIG. 103 is a schematic diagram showing the configuration of an antennadevice according to the forty-third embodiment of the present inventionand includes its side and plan views. Namely, in FIG. 103, a monopoleantenna is coupled to a support section 754 provided on a conductivesubstrate 751 so that it can move up and down or turn right and left andan antenna element 757 which is a planar antenna is located in theproximity of the support section 754. The monopole antenna can beexpanded or contracted by sliding a stick member 753 in a cylindricalmember 752 and a feeding section 756 is provided at the root of themonopole antenna. In addition, a feeding section 758 is provided inplace on the antenna element 757 and an end of the antenna element 757is connected to the conductive substrate 751. With this configuration,the antenna, when not in use, can be made smaller by contracting it asshown by a dash-dot line in the figure.

FIG. 104 shows that an antenna element 857 which is a planar antenna islocated within a space between a contracted monopole antenna and aconductive substrate 851 and this configuration can make the antennadevice still smaller than the configuration of FIG. 103. It should benoted, however, that this configuration may cause larger interferencebetween the antennas than the case described above.

(Embodiment 44)

FIG. 105 is a schematic diagram showing the configuration of an antennadevice according to the forty-fourth embodiment of the present inventionand includes its side and plan views. Namely, in FIG. 105, an antennacomprised of a zigzag conductive pattern 953 formed on a printed circuitboard 952 (hereinafter referred to as printed antenna) is locatedparallel to a conductive substrate 951 and an antenna element 955 whichis a planar antenna is located in the proximity of the printed antenna.An end of the conductive pattern 953 in the printed antenna is connectedto a feeding section 954 and an end of the antenna element 955 isconnected to the conductive substrate 951. In addition, another feedingsection 956 is connected to a point in the antenna element 955.

It should be noted that as described above, the present embodiment usesa planar printed antenna but a three-dimensional antenna formed bybending or curving such a planar antenna, for example, an L-shapedantenna, a three-edge antenna, a quadrangular-prism antenna, acylindrical antenna, or other antennas such as those shown in FIG. 106may be used. It should be also noted that the conductive pattern 953 isnot limited to that shown in FIG. 105 and for example, other patterns1152 as shown in FIG. 107 may be formed on a printed circuit board 1151.It should be further noted that a section 1153 provided on one side of aconductive pattern 1152 as shown in the two lower figures is the toploading of the antenna.

(Embodiment 45)

FIG. 108 is a schematic diagram showing the configuration of an antennadevice according to the forty-fifth embodiment of the present inventionand includes its side and planviews. As shown in FIG. 108, a cylindricalantenna is used in place of the planar printed antenna according to theforty-fourth embodiment described above and a support member 1252 isinserted therein. Namely, a printed antenna 1253 with a support member1252 as its core is located in the proximity of a conductive substrate1251 and near an end of the printed antenna 1253 where a feeding section1254 is provided, an antenna element 1255 with two bends is located inthe proximity of the conductive substrate 1251 with the antenna planeparallel to the substrate. In addition, an end of the antenna element1255 farther from the printed antenna 1253 is connected to theconductive substrate 1251 and a feeding section 1256 of the antennaelement 1255 is provided independently of the feeding section 1254 ofthe printed antenna 1253.

(Embodiment 46)

FIG. 109 is a schematic diagram showing the configuration of an antennadevice according to the forty-sixth embodiment of the present inventionand includes its side and plan views. Namely, in FIG. 109, a printedantenna 1353 with a support member 1352 as its core is coupled to asupport section 1355 provided on a conductive substrate 1351 so that itcan move up and down or turn right and left and an antenna element 1357which is a planar antenna is located in the proximity of the supportsection 1355. In addition, a feeding section 1358 is provided in placeon the antenna element 1357 and an end of the antenna element 1357 isconnected to the conductive substrate 1351. With this configuration, theantenna, when not in use, can be made smaller by contracting it into aposition parallel to the conductive substrate 1351.

FIG. 110 shows that two separate conductive substrates, that is, aconductive substrate 1451 for a printed antenna 1455 and a conductivesubstrate 1452 for an antenna element 1458 are provided in place of thesingle conductive substrate in the configuration described above. Thisconfiguration can allow adjustment of the distance between both antennasfor optimum arrangement.

FIG. 111 shows that in a configuration similar to that of FIG. 109, anantenna element 1557 which is a planar antenna is located within a spacebetween a contracted printed antenna 1553 and a conductive substrate1551 and this configuration can make the antenna device still smallerthan the configuration of FIG. 109. It should be noted that a shield1559 is provided around the antenna element 1557 to prevent interferencebetween the antennas from increasing.

(Embodiment 47)

FIG. 112 is a schematic diagram showing the configuration of an antennadevice according to the forty-seventh embodiment of the presentinvention and includes its side and plan views. In the antenna deviceaccording to the present embodiment, unlike the configuration of FIG.105, an antenna element 1656 which is a planar antenna is also formed ona printed circuit board 1655. Namely, a printed antenna comprised of azigzag conductive pattern 1653 formed on a printed circuit board 1652 islocated parallel to a conductive substrate 1651 and the antenna element1656 which is patterned on another printed circuit board 1655 is locatedin the proximity of the printed antenna. An end of the conductivepattern 1653 in the printed antenna is connected to a feeding section1654 and an end of the antenna element 1656 is connected to theconductive substrate 1651 through the printed circuit board 1655. Inaddition, another feeding section 1657 is connected to a point in theantenna element 1656.

FIG. 113 shows that in the configuration described above, both aconductive pattern 1753 in a printed antenna and an antenna element 1755which is a planar antenna are formed on a single printed circuit board1755. It should be noted that although the distance between bothantennas cannot be adjusted later, the fabrication of the antenna devicecan be facilitated by forming both antenna patterns on a single board.

FIG. 114 shows that in the configuration of FIG. 113, a printed antennais formed into three-edge shape and a printed circuit board 1852integrally consists of a printed antenna board 1852 b and a planarantenna board 1852 a. It should be noted that the shape of the printedantenna board is not limited to that of FIG. 114 and it may be any ofother shapes such as those shown in FIG. 115 like the forty-fourthembodiment.

FIG. 116 shows that a printed circuit board 2052 in the configuration ofFIG. 113 described above can be folded at a flexible section 2057 tomove perpendicularly to the surface thereof and a printed antenna board2052 b can move up and down with respect to a planar antenna board 2052a.

(Embodiment 48)

FIG. 117 is a schematic diagram showing the configuration of an antennadevice according to the forty-eighth embodiment of the present inventionand includes its side and plan views. In the antenna device according tothe present embodiment, on a single printed circuit board 2152, aconductive pattern 2153 is formed as a printed antenna and an antennaelement 2155 is formed as a planar antenna in the proximity of theconductive pattern 2153. A conductive plate 2158 which is a substratefor the antenna element 2155 is provided through an insulation supportmember 2157 and an end of the antenna element 2155 is connected to theconductive plate 2158. In addition, the whole antenna is supported at asupport section 2160 through an insulation plate 2159 so that it canrotationally move in a direction perpendicular to the antenna plane withrespect to another larger conductive substrate 2151.

It should be noted that in the preceding embodiments, several antennasto be combined with a planar antenna are described and their shapes andpatterns may be those shown in FIGS. 106, 107, and 115 or some othersnot shown.

It should be also noted that in the preceding embodiments, one or twothree-edge antennas are used as a planar antenna but the shape andnumber of antenna elements are not limited to these embodiments.

Next, various antennas which may be used as a planar antenna in thefortieth through forty-eighth embodiments will be descried below withreference to the drawings described above.

FIG. 2(a) shows an antenna element 201 which may be used for theone-element antennas in the preceding embodiments and FIG. 2(b) showsanother antenna device which comprises an antenna element 204 configuredby a linear conductor with four bends, a feeding terminal 202 providedin place on the antenna element 204, and an end 203 connected to aconductive substrate 205 for grounding. The antennas can reduce theirinstallation areas because the antenna elements are bent.

FIG. 4(a) shows an antenna device which comprises an antenna element 401configured to be a dipole antenna configured by a linear conductor withfour bends, a feeding terminal 402 provided in place on the antennaelement, and a point 403 connected to a conductive substrate 405 forgrounding. FIG. 4(b) shows another antenna device which comprises anantenna element 404 configured to be a dipole antenna configured by alinear conductor with eight bends, a feeding terminal 402 provided inplace on the antenna element 404, and a point 403 connected forgrounding. These antenna devices can reduce their installation areasbecause the antenna elements configured to be dipole antennas are bentlike a winding.

FIG. 6(a) shows an antenna device which comprises three monopole antennaelements 601 a, 601 b, and 601 c having two bends and different lengthsand being located on the same plane, and reactance elements 602 a, 602b, 602 c, and 604 connected between the taps of the antenna elements 601a, 601 b, and 601 c and a feeding terminal 603 and between the feedingterminal 603 and a ground terminal 605, respectively, to adjust theirimpedance. FIG. 6(b) shows another antenna device which substitutesantenna elements 606 a, 606 b, and 606 c having four bends for theantenna elements 601 a, 601 b, and 601 c of the antenna device of FIG.6(a) described above.

With these configurations, an antenna device having a desirablebandwidth can be implemented by setting the tuning frequencies of theantenna elements at regular intervals. FIG. 40 shows an example of bandsynthesis performed by an antenna having seven antenna elements and itmay be seen from the figure that a broadband frequency characteristiccan be achieved through such band synthesis even when each antennaelement has only a small bandwidth.

FIG. 8(a) shows that additional reactance elements 808 a and 808 b forband synthesis are provided between antenna elements 801 a, 801 b, and801 c in an antenna device having the configuration similar to that ofFIG. 6(a) described above. FIG. 8(b) shows that additional reactanceelements 808 a and 808 b for band synthesis are provided between antennaelements 806 a, 806 b, and 806 c in an antenna device having theconfiguration similar to that of FIG. 6(b) described above. While in theconfigurations of FIGS. 6(a) and (b), each reactance element 602 a, 602b, or 602 c performs the band synthesis in addition to the impedanceadjustment, the embodiment can facilitate the impedance adjustment andband synthesis because the band synthesis function is separated from theimpedance adjustment.

FIG. 10(a) shows an antenna device which comprises three dipole antennaelements 1001, 1002, and 1003 having four bends and different lengthsand being located on the same plane, and reactance elements 1004, 1005,1006, and 1009 connected between the taps of the antenna elements 1001,1002, and 1003 and a feeding terminal 1008 and between the feedingterminal 1008 and a ground terminal 1010, respectively, to adjust theirimpedance. FIG. 10(b) shows another antenna device which substitutesantenna elements 1011, 1012, and 1013 having eight bends for the antennaelements 1001, 1002, and 1003 of the antenna device of FIG. 10(a)described above.

With these configurations, an antenna device having a desirablebandwidth can be implemented by setting the tuning frequencies of theantenna elements at regular intervals.

FIG. 12(a) shows that additional reactance elements 1214, 1215, 1216,and 1217 for band synthesis are provided between antenna elements 1201,1202, and 1203 at two separate locations in an antenna device having theconfiguration similar to that of FIG. 10(a) described above. FIG. 12(b)shows that additional reactance elements 1214, 1215, 1216, and 1217 forband synthesis are provided between antenna elements 1211, 1212, and1213 at two separate locations in an antenna device having theconfiguration similar to that of FIG. 10(b) described above. While inthe configurations of FIGS. 10(a) and (b), each reactance element 1004,1005, or 1006 performs the band synthesis in addition to the impedanceadjustment, the embodiment can facilitate the impedance adjustment andband synthesis because the band synthesis function is separated from theimpedance adjustment.

FIG. 13(a) shows an antenna device which comprises three dipole antennaelements 1301, 1302, and 1303 having different lengths and being formedon a printed circuit board 1304. FIG. 13(b) shows another antenna deviceof the configuration similar to that of FIG. 13(a) described above,which has a conductive substrate 1308 formed on the opposite side of theprinted circuit board 1304 to the antenna element 1320. Such aconfiguration where a printed circuit board is used to form the antennaelements 1301, 1302, and 1303 (1305, 1306, 1307) and the conductivesubstrate 1308 can save the space necessary for an antenna device aswell as allow easy fabrication of the antenna device with improvedperformance reliability and stability.

FIG. 14(a) shows an antenna device which comprises three dipole antennaelements 1401, 1402, and 1403 having different lengths and being formedon a printed circuit board 1404 and two conductors 1405 formed on theopposite side of the printed circuit board 1404 to the antenna element1410 in a direction perpendicular to the antenna element. FIG. 14(b)shows another antenna device of the configuration similar to that ofFIG. 14(a) described above, which has a conductive substrate 1406located in close proximity on the opposite side to the antenna element1410. This conductive substrate 1406 may be formed on the printedcircuit board through a multilayer printing technique. The configurationdescribed above can allow easy fabrication of elements for bandsynthesis.

FIG. 15 shows an antenna device which has antenna elements 1501, 1502,and 1503 located within a recess 1505 in a conductive substrate 1504.This configuration can eliminate any protrusion from an automobile bodyand improve the directional gain performance through interaction betweenthe edge of the antenna element 1510 and the conductive substrate 1504.

The antenna device of FIG. 16(a) comprises an antenna 1610 consisting ofantenna elements 1601, 1602, and 1603 and an antenna 1620 consisting ofantenna elements 1606, 1607, and 1608 and these antennas 1610 and 1620are located in the same plane and within a recess 1605 in a conductivesubstrate 1604. It should be noted that the antennas 1610 and 1620 aredifferent from each other in size and shape but they may be of the samesize and shape. Feeding sections of these antennas are located in theproximity of each other. FIG. 16(b) shows that a similar antenna islocated in the proximity of a planar conductive substrate 1609.

The antenna device of FIG. 17(a) comprises an upper antenna 1710consisting of antenna elements 1701, 1702, and 1703 and a lower antenna1720 also consisting of antenna elements 1701, 1702, and 1703 and theseantennas 1710 and 1720 are located at two levels and within a recess1705 in a conductive substrate 1704. It should be noted that theantennas 1710 and 1720 are of the same size and shape but they may bedifferent from each other in size and shape. FIG. 17(b) shows that asimilar antenna is located in the proximity of a planar conductivesubstrate 1706. If the antennas are of the same size, they will have thesame tuning frequency. Therefore, the bandwidth of the whole antennadevice is the same as that of a single element but this embodiment canimplement a high-gain and high-selectivity antenna because the overallgain of the antenna device can be improved as compared with asingle-element implementation by accumulating the gain of each antennaelement, as shown FIG. 41.

The antenna device of FIG. 18(a) comprises three antennas 1801, 1802,and 1803 each having one or more bends and a plurality of dipole antennaelements and these antennas are formed to be a multilayer printedcircuit board 1806 and located within a recess 1805 in a conductivesubstrate 1804. It should be noted that the three antennas 1801, 1802,and 1803 are of the same size and shape but they may be different fromeach other in size and shape. It should be also noted that the threeantennas are layered in this embodiment but four or more antennas may belayered. FIG. 18(b) shows that a similar antenna is located in theproximity of a planar conductive substrate 1807. As described above,this embodiment can implement a high-gain and high-selectivity antennaeasily by forming a plurality of antennas as a multilayer printedcircuit board.

FIG. 19(a) shows an antenna device which has two linear conductors 1902and 1903 bending in opposite directions to each other with respect to afeeding point 1901 and FIG. 19(b) shows another antenna device which hastwo linear conductors 1904 and 1905 bending in the same direction withrespect to a feeding point 1901. This shape can allow implementation ofa compact planar nondirectional antenna.

FIG. 20(a) shows an antenna device having an antenna element 2002 inwhich the length between a feeding section 2001 and a first bend P isrelatively longer than the length between the first bend P and a secondbend Q. FIG. 20(b) shows an antenna device having an antenna element2002 in which the length between a feeding section 2001 and a first bendP is relatively shorter than the length between the first bend P and asecond bend Q. This shape can allow the antenna device to be installedin a narrow area.

It should be noted that the configuration described above has two linearconductors with respect to a feeding section but the number of linearconductors is not limited to that of this embodiment and may be onlyone. In addition, the number of bends is not limited to that of thisembodiment. It should be noted that the configuration described abovehas two linear conductors with respect to a feeding section but thenumber of linear conductors is not limited to that of this embodimentand may be only one. In addition, the number of bends is not limited tothat of this embodiment.

It should be also noted that the linear conductors in the configurationdescribed above are bent but they may be curved or spiralled. Forexample, as shown in FIG. 21(a), this embodiment may have two linearconductors 2102 and 2103 curving in opposite directions to each otherwith respect to a feeding section 2101 or two linear conductors 2104 and2105 curving in the same direction with respect to a feeding section2101. Also, as shown in FIG. 21(b), this embodiment may have two linearconductors 2106 and 2107 spiralling in opposite directions to each otherwith respect to a feeding section 2101 or two linear conductors 2108 and2109 spiralling in the same direction with respect to a feeding section2101.

When such an antenna is fabricated, an antenna element can be formed, ofcourse, by working metal members but it may be formed throughprinted-wiring on a circuit board. Such a printed-wiring technique canallow easy fabrication of an antenna as well as provide a more reliablecompact antenna at a reduced cost.

The antenna device of FIG. 22 is located in the proximity of aconductive substrate with its ground terminal connected to thesubstrate. For example, as shown in FIG. 22(a), an antenna element 2201is located in the proximity of a substrate 2204 with its ground terminal2203 connected to the substrate 2204. It should be noted that in thisantenna device, a feeding terminal 2202 is provided via a through-holeof the conductive substrate 2204. Such a configuration can provide adesired impedance characteristic and directivity.

FIG. 22(b) shows that a switching element is provided between a groundterminal and a conductive substrate in the antenna. As shown in thefigure, a switching element 2205 is provided between a ground terminal2203 of an antenna element 2201 and a conductive substrate 2204 toselect which state, that is, whether or not the ground terminal isconnected to the conductive substrate can effect the optimum radio-wavepropagation. For this purpose, the switching element 2205 may beremotely operated to control the antenna device depending on the stateof a received wave. This antenna device is used for a verticallypolarized wave if the ground terminal 2203 is connected to thesubstrate, while it is used for a horizontally polarized wave if theground terminal is not connected to the substrate.

It should be noted that the feeding terminal 2202 is provided via athrough-hole of the conductive substrate 2204 in FIG. 22(b) but itslocation is not limited to this embodiment and that, as shown in FIG.23, a feeding terminal 2302 and a ground terminal 2303 may be not topenetrate the conductive substrate 2304.

FIG. 24 shows the positional relationship between the antenna and theconductive substrate in the antenna device having the configurationdescribed above. As shown in FIG. 24(a), a conductive substrate 2402plane and an antenna 2401 plane are located parallel to each other at adistance of h. The directivity of the antenna 2401 can be changed to adesired direction by controlling the distance h. The tuning frequency israised if the antenna 2401 is closer to the conductive substrate 2402,while the tuning frequency is lowered if the antenna is more distantfrom the substrate. Therefore, the antenna device may be configured tocontrol the distance h depending on the state of a received wave. Thecontrol of the distance h may be accomplished, for example, by using afeed or slide mechanism (not shown) to move the antenna 2401 in adirection perpendicular to the antenna plane or by inserting aninsulation spacer (not shown) between the antenna 2401 and theconductive substrate 2402 and moving the spacer in a direction parallelto the antenna plane to adjust the length of the spacer insertion. Also,the size of the spacer may be determined to obtain a desired antennaperformance during the fabrication of the antenna. It should be notedthat a spacer between the substrate and the antenna may be made of alow-permittivity material such as expanded styrol.

As shown in FIG. 24(b), the conductive substrate 2402 plane and theantenna 2403 plane may be located to form a predetermined angle θ (inthis case, 90 degrees) between them. The directivity of the antenna 2403can be controlled by adjusting the angle θ through a hinge mechanism.

It should be further noted that the number of antenna elements may betwo or more. It should be also noted that the substrate consists of asingle conductor according to this embodiment but the body of anautomobile may be used as the substrate.

FIG. 25(a) shows that a plurality of antenna elements 2501, 2502, and2503 are served by a single feeding mechanism to provide an antennaconsisting of the group of antenna elements. For example, a broadbandantenna which covers a desired bandwidth as a whole can be implementedby covering a different bandwidth with each of the antenna elements.Particularly, in the arrangement of FIG. 25(a), the outer antennaelement 2501 is necessarily longer than the inner antenna element 2503and it is easy to set the longer antenna element 2501 to a lower tuningfrequency and the shorter antenna element 2503 to a higher tuningfrequency, so that an antenna covering a broad band as a whole can beimplemented. As shown in FIG. 25(b), a plurality of antenna elements maybe separately arranged in an antenna plane without winding round eachother. If each of the antenna elements covers the same band, theefficiency of the antenna can be improved.

To provide isolation between the antenna elements, a distance betweenthem may be determined to keep them in predetermined isolation or anisolator or reflector may be connected to each of the antenna elements.It should be noted that the number of antenna elements is two or threein this antenna but it is not limited to this embodiment and may be anynumber equal to or more than two.

The antenna device of FIG. 26(a) has antenna elements 2601, 2602, and2603 or antenna elements 2604, 2605, and 2606 layered in a directionperpendicular to the reference plane. It should be noted that theantenna elements may be arranged so that they are all exactly overlaidon the surface of projection as shown in the left of the figure or sothat they are partially overlaid as shown in the right of the figure orso that they are separate from each other. FIG. 26(b) is a partialbroken view showing an application of this embodiment, in which antennas2611 and 2612 are formed on a multilayer printed circuit board 2609through a printed-wiring technique and the antennas are arranged to bepartially overlaid on the horizontal plane. Both elements can be coupledin place by running a conductor through a through-hole 2610.

FIG. 27(a) shows an example of a single antenna feeding section forserving a plurality of antenna elements. As shown in FIG. 27(a), antennaelements 2701, 2702, and 2703 have taps 2704, 2705, and 2706 formed inplace thereon, respectively, to connect them to a feeding terminal 2707.It should be noted that the direction for tapping is identical for allthe antenna elements but it may be arbitrarily determined for each ofthem.

FIG. 27(b) shows an antenna having a common electrode between the tap ofeach antenna element and a feeding terminal. As shown in the figure,taps 2704, 2705, and 2706 are formed in place on antenna elements 2701,2702, and 2703, respectively and a common electrode 2708 is providedbetween the taps and a feeding terminal 2707. This makes theconfiguration simple and in addition, a more compact antenna can beimplemented by placing the electrode 2708, for example, parallel to theoutermost antenna element 2701.

FIG. 28 shows an antenna with each antenna element tapped through areactance element. As shown in FIG. 28(a), antenna elements 2801, 2802,and 2803 may be separately connected to a feeding terminal 2807 throughreactance elements 2804, 2805, and 2806, respectively, or as shown inFIG. 28(b), a reactance element 2809 may be provided within a commonelectrode 2808 between a feeding terminal 2807 and taps. In the lattercase, a reactance element may be provided between the feeding terminaland a ground terminal as shown in FIG. 10 described above. By using aproper reactance element in this way, a desired impedance, band, andmaximum efficiency can be achieved. It should be noted that a variablereactance element may be used as such a reactance element foradjustment.

FIG. 29 shows that a plurality of antenna elements 2901, 2902, and 2903are served by a single feeding terminal 2907 provided via a through-holeof a conductive substrate 2909 to the antenna elements to provide anantenna consisting of the group of antenna elements and a groundterminal 2908 of the feeding section is connected to the conductivesubstrate 2909. This configuration can allow a compact high-gain antennato be provided in a plane in the proximity of the conductive substrate.

In the antenna device shown in FIG. 30(a), the tuning frequency iscontrolled by setting a distance between opposed portions 3001 and 3002of an antenna element near its open terminals to a predetermined valueto control the coupling between them.

The coupling between the opposed portions 3001 and 3002 of the antennaelement near its open terminals can be established by providing adielectric 3003 as shown in FIG. 30(b) or by connecting them through areactance element 3004 as shown in FIG. 30(c). For this purpose, thedielectric 3003 may be movably provided to control the coupling or thereactance element 3004 may be implemented with a variable reactance tocontrol the coupling. It should be noted that the number of antennaelements is one according to this embodiment but it may be two or more.

In the antenna device shown in FIG. 31(a), the tuning frequency iscontrolled by setting a distance between open-terminal portions 3101 and3102 of an antenna element and the neutral point 3103 or their opposedportions 3111 and 3112 near the neutral point to a predetermined value.The coupling between the open-terminal portions of the antenna elementand the neutral point or their opposed portions near the neutral pointcan be established, as shown in FIGS. 31(b) and (c) described above, byproviding a dielectric 3104 or by connecting them through a reactanceelement 3105 or 3106. For this purpose, the dielectric 3104 may bemovably provided to control the coupling or the reactance element 3101or 3102 may be implemented with a variable reactance to control thecoupling. It should be also noted that the number of antenna elements isone according to this embodiment but it may be two or more.

In the antenna device shown in FIG. 32(a), a coil 3 3203 has a linearconductor 3201 or 3202 at each end of the coil, a ground terminal 3206is pulled out of the neutral point of the coil 3203, and a tap 3204 isformed in place on the linear conductor (in this case, 3202) to providea feeding terminal 3205 at the end of the tapping cable. As shown inFIG. 32(b), a tap 3204 may be formed in place on a coil 3203 to providea feeding terminal 3205. This configuration can allow the tuningfrequency of the antenna to be adjusted by controlling the number ofturns of coil winding and in addition, it can allow the implementationof a more compact and broadband antenna.

In the antenna device shown in FIG. 33(a), a coil 3307 has a pluralityof linear conductors 3301, 3302, and 3303 or 3304, 3305, and 3306 ateach end of the coil, a ground terminal 3311 is pulled out of theneutral point 3310 of the coil 3307, and a tap 3308 is formed in placeon the linear conductors (in this case, 3304, 3305, and 3306) to providea feeding terminal 3309 at the end of the tapping cable. As shown inFIG. 33(b), a tap 3312 may be formed in place on a coil 3307 to providea feeding terminal 3309. It should be noted that the three linearconductors are provided on each side of the coil in this antenna but itis not limited to this embodiment and may be any number equal to or morethan two.

It should be also noted that the conductors used as antenna elements inthe embodiment described above are all linear but the shape of eachconductor is not limited to this embodiment and any conductor may haveat least one bend or curve or may be spiral.

In the antenna device shown in FIG. 34, a group of linear conductors3401, 3402, and 3403 and another group of linear conductors 3404, 3405,and 3406 are connected to common electrodes 3407 and 3408, respectively,and these electrodes are connected to a feeding section 3411 throughcoils 3409 and 3410, respectively. This configuration can allow thetuning frequency of the antenna to be adjusted by controlling the numberof turns of coil winding and in addition, it can allow theimplementation of a more compact and broadband antenna.

In the antenna device of FIG. 35, two antennas 3501 and 3502 areswitched by a diversity changeover switch 3503 connected to a feedingsection of each antenna to select one of the antennas which can achievethe optimum radio-wave propagation. It should be noted that the numberof antennas is not limited to two as described for this configurationbut it may be three or more. It should be also noted that the type ofantennas is not limited to that shown in FIG. 50 but other types ofantennas as described for the preceding embodiments or different typesof antennas may be used.

In addition, selection of the optimum antenna from a plurality ofantennas may be accomplished by selecting one which can achieve themaximum receiver input or by selecting one which can achieve the minimumlevel of multipath disturbance.

It should be further noted that a feeding section for serving eachantenna element or each antenna consisting of a plurality of antennaelement groups according to the preceding embodiments described abovemay have a balance-to-unbalance transformer, a mode converter, or animpedance converter connected to it.

FIG. 42(a) shows a monopole-type broadband antenna which comprises amain antenna element 4202 having an end connected to a ground 4204, anantenna element 4201 located in the proximity of the main antennaelement 4202 and having a length longer than the antenna element 4202and no end connected to a ground, and an antenna element 4203 having alength shorter than the antenna element 4202 and no end connected to aground. The main antenna element 4202 is provided with a tap which isconnected to a feeding point 4206 through a reactance element 4205 forimpedance adjustment. FIG. 42(b) shows another antenna device which isobtained by forming on a printed circuit board 4207 antenna elements4201, 4202, and 4203 of the antenna device of FIG. 42(a) described abovethrough a printed-wiring technique.

FIG. 43(a) shows a dipole-type broadband antenna which comprises a mainantenna element 4302 having the center connected to a ground 4304, anantenna element 4301 located in the proximity of the main antennaelement 4302 and having a length longer than the antenna element 4302and no portion connected to a ground, and an antenna element 4303 havinga length shorter than the antenna element 4302 and no portion connectedto a ground. The main antenna element 4302 is provided with a tap whichis connected to a feeding point 4306 through a reactance element 4305for impedance adjustment. FIG. 43(b) shows another antenna device whichis obtained by forming on a printed circuit board 4307 antenna elements4301, 4302, and 4303 of the antenna device of FIG. 43(a) described abovethrough a printed-wiring technique.

These configurations can implement a broadband and high-gain antennadevice which is very simple and easy to adjust. It should be noted thata shorter antenna element and a longer antenna element are located inthe proximity of a main antenna element in the configuration describedabove but two or more antenna elements may be located on each side ofthe main antenna.

FIG. 44(a) shows that a conductive substrate 4404 located in theproximity of antenna elements 4401, 4402, and 4403 is almost equal insize to or smaller than the outermost antenna element 4401. Such aconfiguration can improve the gain for horizontally polarized waves ascompared with the case where a conductive substrate is larger than anantenna element.

FIG. 44(b) shows that the antenna device of FIG. 44(a) described aboveis located within a recess in a vehicle body, the case of acommunication device, the wall of a house, or any other device case andthat an antenna ground (conductive substrate) 4404 is not connected to aground for such a case. This configuration can provide a higher gain forboth horizontally and vertically polarized waves.

FIG. 45 shows how far adjacent to a conductive substrate an antennaelement is to be located and FIG. 45(a) is an example where a singleantenna element is located. Namely, the distance h between an antennaelement 4501 (to speak properly, an antenna grounding connection) and aconductive substrate 4502 is set to a value within 0.01 to 0.25 times aslarge as a wavelength λ for the resonance frequency f of the antenna(that is, 0.01λ to 0.25λ). This configuration can implement a high-gainantenna which is very easy to adjust.

FIG. 45(b) is another example where four antenna elements 4503, 4504,4505, and 4506 are located at different distances from a conductivesubstrate 4507, respectively. As shown in FIG. 45(b), when the antennaelements have different lengths, the shorter element can have the higherresonance frequency and the shorter wavelength. Therefore, the distanceh1 for the shortest antenna element 4506 may be set to the smallestvalue, the distance h2 for the longest antenna element 4503 may be setto the largest value, and the distances for the medium antenna elements4504 and 4505 may be set to values depending on the wavelengths at theirresonance frequencies, respectively. Then the distance between each ofthe antenna elements 4503, 4504, 4505, and 4506 and the conductivesubstrate 4507 must satisfy the condition that it falls within the rangeof 0.01 to 0.25 times as large as a wavelength λ for the resonancefrequency f of each antenna element (that is, 0.01λ to 0.25λ).

FIG. 46 shows that a high-permittivity material is provided between anantenna element 4601 and a conductive substrate 4602. Therefore, thisconfiguration can apply to any other embodiment where a conductivesubstrate is located in the proximity of an antenna element. It shouldbe also noted that the distance between the antenna element and theconductive substrate can be reduced equivalently by providing such ahigh-permittivity material between them.

FIG. 50(a) shows that an antenna 5002 of three antenna elements isinstalled parallel to a conductive substrate 5001 at a distance and agrounded end of the antenna 5002 is connected to the conductivesubstrate 5001, which faces toward the outside. This antenna hassymmetrical directional characteristics on the upper region of theconductive substrate 5001 corresponding to the area covered by theantenna 5002 (on the opposite side to the antenna 5002) and on the lowerregion thereof as shown in FIG. 50(b). Therefore, even if the antenna5002 and the conductive substrate 5001 are located inversely, it canachieve the same effect as those of the antennas according to thepreceding embodiments described above. In addition, even if a conductivesubstrate 5003 is formed as a sealed case as shown in FIG. 50(c), anantenna 5002 inside the conductive substrate 5003 can have similarcharacteristics and communicate with the outside through the conductivesubstrate 5003 when it is fed.

FIG. 51 shows an example of an antenna device of balanced type which canachieve the same effect as those described above, while FIG. 50 shows anantenna device of unbalanced type.

FIG. 55 shows that a conductive substrate 5501 and an antenna 5502installed parallel to and in the proximity of the substrate can beturned (or rotated) together on the axis as shown by a dash-dot line. Asshown in FIG. 55(a), when an antenna 5502 is in a vertical position, theelectric field is horizontal as shown in the right of the figure and itssensitivity for horizontally polarized waves becomes high. As shown inFIG. 55(b), when the antenna 5502 is in a horizontal position, theelectric field is in turn vertical as shown in the right of the figureand its sensitivity for vertically polarized waves becomes high andtherefore, the antenna can be directed in the optimum position dependingon the state of polarized waves. Of course, it may be directed in atilted position.

FIG. 56(a) shows the configuration of another antenna device which canachieve the same effects as those described above without turning theantenna. Namely, a ferroelectric 5603 is located between a conductivesubstrate 5601 and an antenna 5602 so that it can sandwich the antenna5602. As shown in the right of FIG. 56(b), this configuration can allowthe electric field between a conductive substrate 5604 and an antenna5605 to be extended in a horizontal direction through a ferroelectric5606, so that the vertical component is decreased and the horizontalcomponent is increased as compared with the case where no ferroelectricis used as shown in the left of the figure. The antenna can be set forvertically polarized waves or horizontally polarized waves depending onwhether a ferroelectric is used or not. It should be noted that if theantenna is installed in a vertical position, such a ferroelectric willhave an inverse effect on the antenna. It should be further noted thatthe ferroelectric 5603 may be installed during the manufacture or laterand it may be made easily removable by providing grooves for thispurpose.

FIG. 57(a) shows that a linear antenna 5702 with three elements islocated in the proximity of the surface of an elongate platelikeconductive substrate 5701. FIG. 57(b) shows that a linear antenna 5704with three elements is located in the proximity of the surface of acylindrical conductive substrate 5703 so that each element is at thesame distance from the conductive substrate 5703. FIG. 57(c) shows thata linear antenna 5706 with three elements is located in the proximity ofthe surface of a quadrangular-prism conductive substrate 5705 so thateach element is at the same distance from the conductive substrate 5705.

FIG. 58 shows variations of the embodiment shown in FIG. 57, in whichelements are curved or bent in accordance with a curved or bentconductive substrate. FIG. 58(a) shows that an antenna 5802 with threecurved elements is located in the proximity of the surface of a curvedcylindrical conductive substrate 5801 so that each element is at thesame distance from the conductive substrate 5801. FIG. 58(b) shows thatan antenna 5804 with three bent elements is located in the proximity ofthe surface of a bent quadrangular-prism conductive substrate 5803 sothat each element is at the same distance from the conductive substrate5803. FIG. 58(c) shows that an antenna 5806 with three bent elements islocated in the proximity of the surface of a bent platelike conductivesubstrate 5805.

In addition, FIG. 59(a) shows that an antenna 5902 is located along thesurface of a cylindrical conductive substrate 5901 and FIG. 59(b) showsthat an antenna 5904 is located along the surface of a sphericalconductive substrate 5903.

It should be noted that the antenna of this configuration is locatedoutside a component which constitutes a conductive substrate but it isnot limited to this embodiment and it may be located inside a platelikecomponent or on the inner surface of a cylindrical component.

The antenna device shown in FIGS. 60(a) and 60(b) comprises an antenna6002 with three longer elements and an antenna 6003 with three shorterelements with respect to an grounded point connected to a conductivesubstrate 6001 and feeding points A 6005 and B 6004 are provided forthese antennas 6002 and 6003, respectively. As shown in FIG. 60(c), theshorter antenna 6003 is tuned to the A band of relatively higherfrequencies and the longer antenna 6002 is tuned to the B band ofrelatively lower frequencies, and thus, such a single antenna device canaccommodate two tuning bands. It should be noted that the feeding pointsA 6005 and B 6004 may be connected to each other.

FIGS. 61(a) and 61(b) show another example of the antenna of unbalancedtype having two tuning bands. This antenna is a four-element antennahaving an end connected to a conductive substrate 6101 and located inthe proximity of the conductive substrate 6101 and in addition, anantenna 6102 with two relatively longer elements is provided with afeeding point B 6104 and an antenna 6103 with two relatively shorterelements is provided with a feeding point A 6105. As shown in FIG.61(c), this configuration can accommodate two tuning bands, that is, theA band of relatively higher frequencies and the B band of relativelylower frequencies in a similar manner to that described above. It shouldbe also noted that the feeding points A 6005 and B 6004 may be connectedto each other.

FIGS. 62(a) and 62(b) show still another example of the antenna ofbalanced type having two tuning bands. This antenna is a four-elementantenna having the midpoint connected to a conductive substrate 6201 andlocated in the proximity of the conductive substrate 6201 and inaddition, an antenna 6202 with two relatively longer elements isprovided with a feeding point B 6204 and an antenna 6203 with tworelatively shorter elements is provided with a feeding point A 6205. Asshown in FIG. 62(c), this configuration can accommodate two tuningbands, that is, the A band of relatively higher frequencies and the Bband of relatively lower frequencies in a similar manner to thatdescribed above. It should be also noted that the feeding points A 6005and B 6004 may be connected to each other. This configuration canprovide an advanced antenna device which requires a minimum space forinstallation and which is capable of accommodating a plurality of tuningbands, and thus, such an antenna can be applicable in a narrow spacesuch as an automobile or a portable telephone. It should be noted thatthis embodiment assumes two tuning bands but it may accommodate three ormore bands. The latter case can be accomplished by providing a pluralityof antennas each of which has an element length corresponding to eachtuning band and providing a feeding point for each antenna.

In the antenna device shown in FIG. 67, a coil 6703 is inserted in placeon a three-edge antenna element 6701 located in the proximity of aconductive substrate 6702 and an end of the antenna element 6701 isconnected to the conductive substrate 6702. In addition, a feedingsection 6704 is provided on the antenna element 6701 between the coil6703 and the conductive substrate 6702. This configuration can allow anelectric current to concentrate in the coil and thus the antenna devicecan be reduced in size with the gain unchanged. For example, if theantenna element consists of a strip line, the area for the antenna canbe reduced to a quarter. Moreover, its bandwidth can be narrowed and theband characteristics can be sharpened.

FIG. 68 shows that two antenna elements having the configuration of FIG.67 are connected in parallel for band synthesis. Namely, two antennaelements 6801 a and 6801 b having different bands (lengths) and coils6803 a and 6803 b provided in place on the elements, respectively, arelocated in parallel and an end of each element is connected to aconductive substrate 6802. In addition, the antenna elements 6801 a and6801 b are commonly connected to a feeding section 6804 throughreactance elements 6805 a and 6805 b, respectively. This configurationcan synthesize the bands of the two antenna elements and thus, abroadband antenna device with the same effects as those described abovecan be implemented.

In the antenna device shown in FIG. 69, a coil 6903 is provided betweenan end of a three-edge antenna element 6901 located in the proximity ofa conductive substrate 6902 and the conductive substrate 6902 and theother end of the coil 6903 is connected to the conductive substrate 6902for grounding. In addition, a feeding section 6904 is provided in placeon the antenna element 6901. This configuration can allow an electriccurrent to concentrate in the coil and thus the antenna device can bereduced in size with the gain unchanged.

FIG. 70 shows that two antenna elements having the configuration of FIG.69 are connected in parallel for band synthesis. Namely, two antennaelements 7001 a and 7001 b having different bands (lengths) are locatedin parallel with an end connected in common to an end of a coil 7003 andthe other end of the coil 7003 is connected to a conductive substrate7002. In addition, the antenna elements 7001 a and 7001 b are connectedto a feeding section 7004 in common through reactance elements 7005 aand 7005 b, respectively. This configuration can synthesize the bands ofthe two antenna elements and thus, a broadband antenna device with thesame effects as those described above can be implemented. It should benoted that the single coil which is shared by the two antenna elementscan contribute to a simple configuration.

In the antenna device shown in FIG. 71, an insulator 7105 is provided ona conductive substrate 7102 and an antenna element 7101 and a coil 7103are connected on the insulator 7105. This configuration can allow easyinstallation of a coil 7103, which is useful for its implementation, andthus the coil can be stably installed. FIG. 72 shows the configurationof two antenna elements 7201 a and 7201 b arranged for band synthesisand that although the connection between a coil 7203 and the antennaelements becomes more complex because of the more antenna elements ascompared with the case of FIG. 71, a connection point provided on aninsulator 7205 on a conductive substrate 7202 can make the connectionbetween the antenna elements and the coil much easier.

In the antenna device shown in FIG. 73, a coil section are divided totwo parts and two insulators 7305 a and 7305 b are provided on aconductive substrate 7302 to connect antenna elements and coils. Namely,an end of a three-edge antenna element 7301 provided in the proximity ofa conductive substrate 7302 and an end of a coil 7303 a are connectedtogether on an insulator 7305 a, the other end of the coil 7303 a and anend of another coil 7303 b and a feeding section 7304 are connectedtogether on another insulator 7305 b, and the other end of the coil 7303b is connected to the conductive substrate 7302 for grounding. FIG. 74shows an antenna device having two antenna elements 7401 a and 7401 barranged for band synthesis and the antenna elements, coils, and afeeding section are connected in a similar manner to that shown in FIG.73. These configurations can allow easy connection to other circuitcomponents because the feeding terminal is provided on a circuit board.

In the antenna device shown in FIG. 75, a zigzag pattern 7503 isinserted in an antenna element 7501 in place of the coil for theconfiguration of FIG. 67. Although the configuration having a coil canthree-dimensionally extend, the configuration with this pattern 7503 canbe formed on the same plane as the antenna element 7501 and fabricatedthrough a printed-wiring technique. FIG. 76 shows an antenna devicehaving two antenna elements 7601 a and 7601 b arranged for bandsynthesis and zigzag patterns 7603 a and 7603 b are inserted in antennaelements 7601 a and 7601 b, respectively. It should be noted that thezigzag patterns may be sawtoothed ones as shown in FIG. 78 In theantenna device shown in FIG. 77, the whole antenna element 7701 locatedin the proximity of a conductive substrate 7702 is formed in a zigzagpattern and an end of the antenna element 7701 is connected to an end ofa coil 7703 which is grounded at the other end. In addition, a feedingsection 7704 is provided in place on the zigzag antenna element. Thisconfiguration can allow the antenna device to be further reduced insize, for example, to ⅙ or ⅛, although possible losses may be increased.It should be noted that the antenna element may be formed in otherpatterns, for example, those shown in FIGS. 78(b) and (c). The patternshown in FIG. 78(b) is a three-dimensional coil.

In the antenna device shown in FIG. 79, an insulator 7904 is provided ona conductive substrate 7902 and a lead 7905 from an antenna element 7901and a feeding section 7903 are connected together on the insulator 7904.This configuration can allow easy connection with other circuitcomponents because the feeding section 7903 is provided on a circuitboard.

FIG. 80 shows that a through-hole 8005 is formed in a conductivesubstrate 8002 to provide an insulator 8004 on the opposite side of theconductive substrate 8002 to an antenna element 8001. A lead 8006 fromthe antenna element 8001 passes through the through-hole 8005 and theinsulator 8004 and connects to a feeding section 8003 on the insulator8004. This configuration can make it much easier than that of FIG. 79described above to connect other circuit components to the feedingsection 8003 because such circuit components can be connected on theback of the conductive substrate 8002.

FIG. 81 shows that in addition to the configuration of FIG. 80 describedabove, another conductive plate is provided on the back of a conductivesubstrate (on the opposite side to an antenna element) to mount variouscircuit components thereon. Namely, a through-hole 8104 is formed inboth a conductive substrate 8102 and a conductive plate 8105 to run alead 8111 from an antenna element 8101 therethrough and an insulator8103 is provided on the conductive plate 8105 over the through-hole8104. In addition, a required number of insulators 8106 are provided onthe conductive plate 8105 to connect various circuit components. Thelead 8111 passes through the through-hole 8104 to the insulator 8103 andcircuit components 8107 to 8110 are connected on the insulators 8103 and8106. This configuration can allow location of the circuit in theproximity of the antenna and easy shielding between the antenna and thecircuit through the conductive plate, and thus, it can facilitateimplementing a compact device.

FIG. 82 shows still another example of the antenna in which circuitcomponents are located on the same side as an antenna element. Namely,an insulator 8203 to connect a lead 8205 from an antenna element 8201and a required number of insulators 8206 to connect various circuitcomponents are provided on a conductive substrate 8202. In addition, aconductive shielding case 8204 is provided on the conductive substrate8202 to shield the circuit components on the conductive substrate 8202from the antenna element 8201 and a through-hole 8207 is formed forrunning the lead 8205 therethrough. The lead 8205 passes through thethrough-hole 8207 to connect to the insulator 8203 and circuitcomponents 8208 to 8210 are connected on the insulators 8203 and 8206.An end of the antenna element 8201 is connected to the shielding case8204 for grounding. This configuration can allow the whole circuit to beheld between the antenna element and the conductive substrate and to beshielded by the shielding case, and thus, it can facilitate implementinga more compact device than the configuration of FIG. 81 described above.

In the antenna device shown in FIG. 83, an antenna element 8301 isformed on one side of an insulation plate 8305 and one end 8307 of theantenna element 8301 passes through the insulation plate 8305. A lead8303 from a point in the antenna element 8301 also passes through theinsulation plate 8305 and another lead 8306 formed on the opposite sideof the insulation plate 8305 and parallel to the antenna element 8305 isconnected to the lead 8303 for connecting a feeding section 8304 to thelead 8306. It should be noted that the feeding section 8304 is providedin the proximity of the end 8307 of the antenna element 8301. Inaddition, the insulation plate 8305 is located parallel to a conductivesubstrate 8302, to which the end 8307 of the antenna element 8301 isconnected. This configuration can facilitate connecting coaxial cablesbecause the grounded end of the antenna element is close to the feedingsection.

In the antenna device shown in FIG. 84, a conductive substrate 8404 isprovided on another broader conductive substrate 8402 through aninsulation plate 8405 and an antenna element 8401 is located in theproximity of the conductive substrate 8404. It should be noted that anend of the antenna element 8401 is connected to the conductive substrate8404 for grounding. It should be preferable that the conductivesubstrate 8404 is equal to the antenna element 8401 in size.Specifically, the conductive substrate 8402 may be the body of anautomobile or carriage, the metal case for a receiver or communicationdevice, or any metal structure of a house and it may be installed insideor outside the room or compartment. This configuration can achieve anearly horizontal elevation angle with the maximum gain and thus, itwill be suitable for receiving communication waves (vertically polarizedwaves) which come from a lateral direction.

FIG. 47 is a schematic diagram showing a possible automobile applicationof an antenna device according to the present invention. Namely, any oneof the antenna devices according to the preceding embodiments describedabove is installed at five locations in total, that is, one on each ofthe four pillars 4701 and one on the roof, to provide a diversityconfiguration of these flat antennas. This configuration can offer agood capability of receiving and transmitting both horizontally andvertically polarized waves. It should be noted that the antenna deviceis installed at five locations according to this embodiment but it maybe installed at more or less locations.

FIG. 48 is a schematic diagram showing possible locations where anantenna device according to the present invention is to be installed forautomobile applications. Namely, any one of the antenna devicesaccording to the preceding embodiments described above is installed atany one or more locations on the roof panel, hood, pillars, side faces,bumpers, wheels, floor, or other surface portions of an automobile body4801. In FIG. 48, an antenna 4802 is installed at a location where theantenna plane is almost in a horizontal position, an antenna 4803 isinstalled at a location where the antenna plane is in a tilted position,and an antenna 4804 is installed at a location where the antenna planeis almost in a vertical position. It should be noted that this figureshows possible locations for antenna installation by way of example andall the locations shown are not provided with antennas. Of course, itshould be also noted that an antenna may be installed at any locationother than those shown. It should be further noted that the automobiletype is not limited to such a passenger car as shown and an antennaaccording to the present invention may be installed on a bus, truck, orany other type of automobile.

In addition, since an antenna 4805 is installed at a location where theantenna plane is in a horizontal position, and specifically, on the back(undersurface) of the floor with its directivity facing the roadbed, itis suitable for communication with a wave source installed on the road(or embedded therein) which is to be used for communication or detectionof vehicle positions.

Generally, airwaves for TV or FM broadcasting mainly consist ofhorizontally polarized waves, while waves for portable telephone orradio communication mainly consist of vertically polarized waves.Whether an antenna is suitable for horizontally polarized waves orvertically polarized waves depends on the direction of its installation.As shown in FIG. 49(a), an antenna 4902 which is installed parallel to aconductive substrate 4901, that is, a vertical surface portion of anautomobile body 4801 and comprises three antenna elements of unbalancedtype with their grounded ends connected together is effective forhorizontally polarized waves, since its sensitivity to horizontallypolarized waves can be raised because of the horizontal electric fieldas shown in the right of the figure. This can be accomplished byinstalling an antenna 4804 as shown in FIG. 48. On the other hand, anantenna 4802 which is installed parallel to a horizontal surface portionof the automobile body 4801 is effective for vertically polarized waves,since its sensitivity to vertically polarized waves can be raisedbecause of the vertical electric field. In addition, an antenna 4803which is installed in a tilted position can be used regardless of thedirection of polarization, since its sensitivity is balanced betweenhorizontally and vertically polarized waves depending on the degree oftilt. FIG. 49(b) shows an example of antenna of balanced type, which iseffective for horizontally polarized waves in a similar manner to thatdescribed above.

FIG. 52 is a schematic diagram showing possible locations where theantenna device according to the present embodiment is to be installedfor automobile applications similar to those of FIG. 48. In FIG. 52,like in FIG. 48, an antenna 5202 is installed at a location where theantenna plane is almost in a horizontal position, an antenna 5203 isinstalled at a location where the antenna plane is in a tilted position,and an antenna 5204 is installed at a location where the antenna planeis almost in a vertical position. In addition, since an antenna 5205 isinstalled at a location where the antenna plane is in a horizontalposition, and specifically, on the inner surface of the floor, it issuitable for communication with a wave source installed on the road in asimilar manner to that of FIG. 48. Although these antennas shown are allinstalled inside an automobile body 5201, they can achieve the sameperformance as that for the antennas installed on the outer surface ofthe automobile body for the reasons described above and in addition,they are very advantageous in appearance, damages, or risk of beingstolen because they are not exposed to the outside of the body.Moreover, as shown in FIG. 52, the antenna device according to thepresent embodiment may be installed on a rearview mirror, in-car sunvisor, number plate, or any other location where it cannot be otherwiseinstalled on the outer surface, by embedding it within the inside spaceof such a component.

If an antenna is to be installed in a vertical position, for example, itmay be installed on the end 3703 of an automobile spoiler 3701 or 3702or the end 3703 of a sun visor as shown in FIG. 37(a) or on a pillarsection 3704 as shown in FIG. 37(b). Of course, installation locationsare not limited to them and the antenna may be installed on any otherlocations which are tilted to some extent with respect to any horizontalplane. Therefore, the reception of a desired polarized wave can be madevery easy by positioning the antenna at such locations.

FIGS. 63 and 65 show applications of the antenna device according to thepresent invention. FIG. 63 shows that an antenna 6302 is installed onthe surface of an elongate roof rail 6303 on the roof of an automobilebody 6301 and FIG. 65 shows that an antenna 6502 is installed inside anelongate roof rail 6503 on the roof of an automobile body 6501.

Moreover, FIGS. 64 and 66 show applications of the antenna deviceaccording to the present invention. FIG. 64 shows that an antenna 6403is installed on the surface of an elongate roof box 6402 on the roof ofan automobile body 6401 and FIG. 66 shows that an antenna 6603 isinstalled inside an elongate roof box 6602 on the roof of an automobilebody 6601.

It should be noted that the antenna device described above is installedon an automobile but it may be installed on other vehicles such as anairplane or ship. Alternatively, it may be installed not only on suchvehicles but also on the roadbed, shoulder, tollgate, or tunnel wall ofany expressway or highway, or on the wall or window of any building.

FIG. 53 is a schematic diagram showing a possible application to aportable telephone of the antenna according to the present invention, inwhich an antenna 5302 is installed inside a conductive grounded case5301 with an antenna ground connected thereto. This configuration canallow the antenna to be used in a similar manner to the case where theantenna is installed outside the grounded case 5301 and it can make theantenna very advantageous in handling because the antenna is not exposedto the outside. It should be noted that the antenna is used with aportable telephone according to this embodiment but it can also apply toa TV, PHS, or other radio set.

FIG. 39(a) shows an example in which a conductive shielding case 3902provided inside a resinous case 3901 of a portable telephone is used asa conductive substrate and an antenna 3903 is located along the innerside of the case 3901 to be parallel to the shielding case 3902. FIG.39(b) shows another example in which an antenna 3904 is located on thetop surface outside a resinous case 3901 of a portable telephone and aconductive substrate 3905 is provided on the inner wall of the case 3901opposite to the antenna 3904. In the latter case, the top of a shieldingcase 3902 is too small to be used as a conductive substrate. Theantennas used in both FIGS. 24(a) and (b) are preferably those havingmore bends or more turns of winding which can easily allow theimplementation of a compact antenna.

With these configurations, the directional gain on the conductivesubstrate side is very small to the antenna and therefore, possibleinfluence of electromagnetic waves on human body can be reduced withoutany degradation of antenna efficiency if the antenna device is used withthe conductive substrate side turned to the user. It should be furthernoted that the antenna device is implemented in a portable telephone butit may apply to other portable radio sets, for example, a PHS device, apager, or a navigation system.

FIG. 54 is a schematic diagram showing a possible application to anordinary house of the antenna according to the present invention.Namely, an antenna 5402 is installed inside a conductive door of a house5401, an antenna 5403 is installed inside a conductive window (forexample, storm window), an antenna 5404 is installed inside a conductivewall, and an antenna 5405 is installed inside a conductive roof.Therefore, when an antenna is installed inside a conductive structure ofthe house 5401 in this way, the antenna can be protected againstweather-induced damage or degradation with an elongated service lifebecause it is not exposed to the outside.

It should be further noted that even if a house consists ofnonconductive structures, such an antenna can be installed at anylocation by attaching a conductor to the outer surface thereof.

As described above, each antenna device according to the presentinvention can be installed without any portion protruding from the bodyplane of an automobile because it can be located with its antenna planeparallel to and in the proximity of the body plane which is a conductivesubstrate and in addition, it can be installed even in a narrow spacebecause it takes up only a small area. Therefore, its appearance can beimproved with little wind soughing brought about around it and inaddition, some other problems such as a risk of its being stolen andlabors involved in removing it before car wash can be eliminated.

FIG. 38 is a schematic diagram showing an example of a mobilecommunication device with an antenna device according to the presentinvention. As shown in FIG. 38, an antenna 3801 according to any one ofthe preceding embodiments described above is installed on the ceiling ofan automobile body 3805. In this case, if the antenna 3801 is locatedwithin a recess 3806 in the ceiling, any portion of the antenna will notprotrude from the outline of the body 3805. As seen from the figure, theantenna 3801 is connected to a communication device 3804 which isinstalled inside the body 3805 and consists of an amplifier 3802 and amodem 3803. It should be noted that the antenna device described aboveis used with a mobile communication device but it may be used with anyother device which receives or transmits radio waves, for example, atelevision set, a radio-cassette player, or a radio set.

(Embodiment 49)

FIG. 118 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to the forty-ninthembodiment of the present invention. In FIG. 118, the reference numeral9001 designates an input means, 9002 designates a delay means, 9003designates a synthesis means, 9004 designates a reception means, 9005designates a demodulation means, 9007 designates a delayed waveestimation means, 9008 designates a positional information determinationmeans, and 9009 designates a vehicle information detection means. Theoperation for receiving digital television broadcasting at a vehiclewill be described below with reference to FIG. 118.

A television broadcasting wave is converted to an electric signal by theinput means 9001 such as a receiving antenna and then supplied to thedelay means 9002 and the synthesis means 9003. The televisionbroadcasting wave converted to such an electric signal is delayed by thedelay means 9002 in accordance with a delay control signal from asynthesis control means 9006 and then supplied to the synthesis means9003. In the synthesis means 9003, in accordance with a synthesiscontrol signal from the synthesis control means 9006, a signal from theinput means 9001 and another signal from the delay means 9002 areprovided with a predetermined gain for each signal and synthesizedtogether and then supplied to the reception means 9004. As a synthesistechnique used for this purpose, addition, maximum selection, or othersimple operations can be used.

The reception means 9004 extracts only signals within a necessary bandfrom those supplied by the synthesis means 9003 and converts them tosignals of frequencies which can be handled by the demodulation means9005. Thus converted signals are supplied to the demodulation means9005, which in turn demodulates them for output. The demodulation means9005 supplies demodulation information to the delayed wave estimationmeans 9007, which estimates a delayed wave contained in the receivedwave based on the demodulation information supplied by the demodulationmeans 9005.

The operations for demodulation and delayed wave estimation will bedescribed below. In the ground wave digital broadcasting which is nowbeing standardized in Japan, orthogonal frequency-division multiplexing(OFDM) is used for modulation and the demodulation means 9005 performsOFDM demodulation to decode transmitted codes. During the decodingprocess, frequency analysis is performed through an operation such asFFT. The transmission characteristics of a received signal can beestimated by using various pilot signals contained in the receivedsignal for data demodulation. For example, a delay time can be detectedby detecting dip locations and the number of dips in frequencycomponents which are obtained from the FFT frequency analysis.

FIG. 124 shows a result of the frequency analysis performed for OFDM andthe frequency characteristics may be flat when no delayed wave exists,while the frequency characteristics may have some dips as shown in FIG.124 when some delayed waves exist. Alternatively, a delayed wave can bedetected by observing any variation in or lack of pilot signals. Thedelay time of a disturbance wave can be estimated based on erroneousdata positional information obtained through an error correction processperformed after the FFT operation. It should be noted that the Japanesedigital broadcasting has been described in the above paragraphs but thistechnique may apply also to analog broadcasting or foreign digitalbroadcasting.

Next, the operations for synthesis control and delay control will bedescribed below. The synthesis control means 9006 provides a signal tocontrol the delay means 9002 and the synthesis means 9003 based onestimated delayed wave information supplied by the delayed waveestimation means 9007. The configuration of the synthesis control means9006 which comprises a gain control means 9061 and a delay time controlmeans 9062 will be described below. The gain control means 9061establishes a synthesis gain in the synthesis means 9003 based ondelayed wave information supplied by the delayed wave estimation means9007. This establishing operation will be described below with referenceto FIG. 125. In FIG. 125, the axis of abscissas shows the magnitude of adelayed wave and the axis of ordinates shows a ratio of the gain of asignal supplied by the input means 9001 (signal A gain) to the gain of asignal supplied by the delay means 9002 (signal B gain) (=signal Again/signal B gain). The synthesis gain is controlled so that both gainscan be identical when the level of a delayed wave is small, or it islarge and in particular, it is equal to the level of a direct wave or sothat a difference between both gains can be obtained by decreasing thegain of a signal supplied by the delay means or that of a signalsupplied by the input means when the level of a delayed wave is small,or it is larger than that of a direct wave. In addition, if the gaincontrol is accomplished based on the delay time of a delayed wavesupplied by the delayed wave estimation means 9007, the gain differencebecomes larger for the case of a large delay time (the curve a in FIG.125) than the case of a small delay time (the curve b in FIG. 125).

Next, the operation of the delay time control means 9062 will bedescribed below. It controls the establishment of a delay time to beused by the delay means 9002 so that the delay means 9002 delays thetime by a length almost equal to the delay time estimated by the delayedwave estimation means 9007. For example, the relationship between errorrates of a delayed wave and a demodulated signal is shown in FIG. 126.As shown in the figure, although the error rate may deteriorate abruptlywhen a delay time is small (point B: about 2.5 μs or less), such adeterioration in error rate can be effectively avoided by using a fixeddelay time, for example, a delay time exceeding the point B in FIG. 126,rather than a delay time estimated by the delayed wave estimation means9007 when the estimated delay time is small. It should be noted thatsuch a delay time to be established here must be at most shorter than aguard period added to an OFDM signal. In order to prevent such adeterioration in error rate from occurring due to the small delay timeof a delayed wave, the delay means 9002 can always establish apredetermined delay time. For this purpose, any influence of a shortdelay time can be eliminated by setting such a delay time to a valuenearly twice as large as the point B. If a signal is received by asingle antenna as shown in FIG. 118, a delay time smaller than thereciprocal of the bandwidth of a received signal can be added to thesignal to decrease the noise level of the received signal with animproved error rate. This is because dips caused by the added signalwill appear outside the signal bandwidth. For example, if the signalbandwidth is 500 kHz, a delay time must be established to be 2 μs orless. The operation for adding a signal with a short delay time asdescribed above can be effective in improving the reception level ofsignal bandwidth for narrowband broadcasting which is used asbroadcasting services for mobile communication.

Next, the usage of the vehicle information detection means 9009 will bedescribed below. The vehicle information detection means 9009 detectsinformation on a moving reception vehicle. For example, this means mayconsist of a speed (vehicle speed) detection means 9091 which detectsthe speed of a moving reception vehicle and a position detection means9092 which detects the position of such a vehicle. It goes withoutsaying that the vehicle information detection means 9009 can beimplemented by a navigation system and that the position detection meanscan be implemented by using a GPS system or by detecting locationsthrough a PHS, a portable telephone set, or a traffic control systemsuch as VICS. Detected vehicle information is supplied to the positionalinformation determination means 9008.

The positional information determination means 9008 checks whichbroadcast station covers the current location and estimates the delaytime and the strength of a wave received at the receiving location,taking account of the distance from such a station as well as possiblereflections from mountains and buildings. To this end, this means haspreviously obtained information including the transmission frequency andlocation or transmission power of each transmitting station such as abroadcast station or relay station or downloaded it through anycommunication means such as broadcasting or telephone into its storageto compare it with the positional information supplied by the vehicleinformation detection means 9009 for estimation. From this information,the delay time and magnitude of a wave received at that receivinglocation can be estimated.

Moreover, the delay time and magnitude of a received wave can beobtained more accurately, by marking in a map information including thelocation, magnitude, and height of each building located near thereceiving location in addition to the location of each broadcastingstation and taking account of possible reflections therefrom. It goeswithout saying that a navigation system can be used to handle suchinformation on the transmitting stations, buildings, and mountains. Itshould be also noted that a delayed wave can be tracked more quicklybecause the following delayed wave can be estimated by knowing the speedof a moving reception vehicle through the speed detection means 9091.

The synthesis control means 9006 controls the synthesis gain and thedelay time based on the delayed wave information supplied by thepositional information determination means 9008. These controloperations can be performed in a similar manner to those based on thedelayed wave information supplied by the delayed wave estimation means9007. In addition, the information from the delayed wave estimationmeans 9007 can be used in combination with that from the positionalinformation determination means 8 and then the gain and delay time maybe controlled only if these two kinds of delay information are similarto each other or they may be controlled to remain unchanged or they maybe controlled in accordance with the information containing a largerlevel of delayed wave if these two kinds of delay information are quitedifferent from each other. It should be noted that in the descriptionabove, the vehicle information detection means 9009 is provided formobile reception but both mobile and stationary reception can beaccomplished by using the position detection means 9092 only.

The configuration described above has only one input means as shown inFIG. 118 but another configuration shown in FIG. 119 which has aplurality of input means and a plurality of delay means corresponding tothe input means, respectively, is also effective for mobile reception.Each input means of this configuration is provided with a differentinput signal because it is affected by a different level of multipathinterference even when it receives the same broadcasting wave. This maycause dips at different locations (frequencies) and different depths asshown in FIG. 124. Therefore, a plurality of different input signals canbe added together to provide another signal at a different location anddepth, resulting in a lower signal error rate. The reception operationof the device shown in FIG. 119 is almost identical to that describedfor FIG. 118. Under the control of the delay means 9002 and thesynthesis means 9003, a desired delay time is established with the delaymeans 1 through N in a relative manner and the gain can be set inaccordance with the delayed signal. If the distance between antennalocations is sufficiently shorter than the wavelength of the baseband,the level of received signals can be improved by adding a plurality ofinput signals within the baseband.

As described above, the digital television broadcasting receiving deviceaccording to the forty-ninth embodiment can reduce signal dips throughanalysis of a plurality of signals, resulting in an improved error rateof digital data. Any deterioration in error rate can be avoided byestablishing a delay time to prevent any influence of a signal with ashorter delay time. In addition, signal dips can be avoided moreaccurately by producing an accurate delayed wave through the delayedwave estimation means, the vehicle information detection means, and thepositional information determination means and thus, the error rate canbe further improved.

Signals received through a plurality of antennas can be switcheddepending on their error conditions. The antenna switching conditionsfor changing over from one antenna to another will be described belowwith reference to FIG. 127. First, the C/N ratio of an input signal andthe length of a past period such as a frame period thereof aredetermined and antenna switching is not performed if the C/N ratio islarge and the error rate is low. If an error is a burst one of veryshort period and does not continue for a while even when the error rateis high, antenna switching is not performed. If the C/N level of aninput signal is lowered or if a high error rate continues for a while,antenna switching is performed. The timing for antenna switching may beset to a guard interval appended to an OFDM signal. Alternatively, suchan antenna switching timing may be calculated from a combination ofvehicle speed information and positional information. It should be notedthat the timing for antenna switching may be set to a guard intervalappended to an OFDM signal. This can allow optimum antenna switching inaccordance with varying reception conditions during the mobilereception. It should be also noted that by providing an antenna 9011 andan amplification means 9012 as components of the input means shown inFIGS. 118 and 119, any signal attenuation or matching loss due todistribution can be avoided to perform the succeeding operationaccurately.

(Embodiment 50)

FIG. 120 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to the fiftiethembodiment of the present invention. In FIG. 120, the reference numeral1 designates an input means, 2 designates a delay means, 3 designates asynthesis means, 4 designates a reception means, 5 designates ademodulation means, 7 designates a delayed wave estimation means, 8designates a positional information determination means, and 9designates a vehicle information detection means. The configuration ofthe fiftieth embodiment as shown in FIG. 120 differs from that of theforty-ninth embodiment described above in that the reception means 9004is connected directly to the input means 9001. The operation forreceiving digital television broadcasting at a vehicle according to thefiftieth embodiment will be described below.

A television broadcasting wave is converted to an electric signal by theinput means 9001 such as a receiving antenna and then supplied to thereception means 9004. The reception means 9004 extracts only signalswithin a necessary band from those supplied by the input means 9001 andsupplies them to the delay means 9002 and the synthesis means 9003.Those signals supplied by the reception means 9004 are delayed by thedelay means 9002 in accordance with a delay control signal from asynthesis control means 9006 and then supplied to the synthesis means9003. In the synthesis means 9003, in accordance with a synthesiscontrol signal from the synthesis control means 9006, a signal from thereception means 9004 and another signal from the delay means 9002 areweighted with a predetermined gain added to each signal and synthesizedtogether and then supplied to the demodulation means 9005. As asynthesis technique used for this purpose, addition, maximum selection,or other simple operations can be used similarly to the forty-ninthembodiment. The demodulation means 9005 demodulates them for output.

In a similar manner to that for the forty-ninth embodiment, a delayedwave is estimated in the delayed wave estimation means 9007 and thepositional information determination means 9008 from demodulationinformation supplied by the demodulation means 9005 and mobile receptioninformation supplied by the vehicle information detection means 9009,respectively, and then supplied to the synthesis control means 9006,which in turn controls the delay and synthesis operations by producingcontrol signals to be supplied to the delay means 9002 and the synthesismeans 9003. The detailed operations of the synthesis control means andthe vehicle information detection means performed during the receptionoperation described above are identical to those for the forty-ninthembodiment. In the receiving device according to the fiftiethembodiment, the operations of the delay means 9002 and the synthesismeans 9003 can be simplified because the frequencies and bands arelimited by the reception means 1, but the same effects as those of theforty-ninth embodiment can be achieved.

As shown in FIG. 121, a plurality of input means 9001, a plurality ofreception means 9004, and a plurality of delay means 9002 can beprovided for reception. The operation of this configuration shown inFIG. 121 is identical to that for the preceding embodiment describedabove and will not be described here in detail. Because a plurality ofinput means 9001, a plurality of reception means 9004, and a pluralityof delay means 9002 are provided, each input means of this configurationis provided with a different input signal due to a different level ofinterference even when it receives the same broadcasting wave. This maycause dips at different locations (frequencies) and different depths asshown in FIG. 124. Therefore, a plurality of different input signals canbe added together to provide another signal at a different location anddepth, resulting in a lower signal error rate.

(Embodiment 51)

FIG. 122 is a block diagram showing the configuration of a digitaltelevision broadcasting receiving device according to the fifty-firstembodiment of the present invention. In FIG. 122, the reference numeral1 designates an input means, 4 designates a reception means, 5designates a demodulation means, 7 designates a delayed wave estimationmeans, 55 designates a demodulation control means, 8 designates apositional information determination means, and 9 designates a vehicleinformation detection means. The operation for receiving digitaltelevision broadcasting at a moving vehicle or a fixed location will bedescribed below with reference to FIG. 122.

A television broadcasting wave is converted to an electric signal by theinput means 9001 such as a receiving antenna and then supplied to thereception means 9004. The reception means 9004 extracts only signalswithin a necessary band from those supplied by the input means 9001 andsupplies them to the demodulation means 9005. The demodulation meansdemodulates the signals supplied by the reception means 9004 to providedigital signals for output and supplies the demodulation conditions tothe delayed wave estimation means 9007.

Now, the operation of the demodulation means 9005 will be describedbelow. More specifically, the operation of the demodulation means 9005consisting of a frequency analysis means 9051, an adjustment means 9052,and a decoding means 9053 will be described. A signal supplied by thereception means 9004 is frequency-analyzed by the frequency analysismeans 9051 which performs an FFT, real FFT, DFT, or FHT frequencyanalysis technique to convert it to a signal on the frequency axis andsuch a converted signal is supplied to the adjustment means 9052. Theadjustment means 9052 operates the signal on the frequency axis from thefrequency-analyzed signal 51 based on a control signal supplied by thedemodulation control means 9055. That operation may be accomplished byperforming a transfer function on a signal supplied by the frequencyanalysis means 9051 based on the control signal from the demodulationcontrol means 9055, by performing an arithmetic operation throughfiltering, by emphasizing a specific frequency component, or byinterpolating a possibly missing frequency component. The signalsupplied by the adjustment means 9052 is decoded by the decoding means9053 into a digital code. The delayed wave estimation means 9007estimates a delayed wave based on a signal from the decoding means 9005.Such reference signals include a frequency spectrum supplied by thefrequency analysis means 9051 and a pilot signal obtained during thedecoding process in the decoding means 9053. The frequency spectrum of areceived signal has dips in response to the presence of delayed waves asshown in FIG. 124. Since the frequency spectrum becomes flat in the ODFMmodulation which is usually used for digital television broadcasting,the magnitude of a delayed wave and the delay time can be estimated. Themagnitude of a delayed wave and the delay time also can be estimatedfrom any change in phase or missing of a pilot signal. The demodulationcontrol means 9055 controls the adjustment means 9052 based on delayedwave information supplied by the delayed wave estimation means 9007 orthe positional information determination means 9008. Such a control canbe accomplished by supplying a control parameter determined inaccordance with the adjustment means 9052 and for example, by supplyinga transfer function determined by the demodulation control means 9055 inaccordance with a delayed wave when the transfer function is to beapplied to the adjustment means 9052. Alternatively, a filter factor issupplied when filtering is to be performed or an interpolation value issupplied when interpolation is to be performed. The positionalinformation determination means 9008 and the vehicle informationdetection means 90092 are identical to those for the forty-ninth andfiftieth embodiments described above and will not be described here indetail.

As described above, according to the present embodiment, accuratedecoding can be accomplished with an improved error rate of receiveddigital signals, since the adjustment means 9052 serves to reduce anyinfluence of delayed waves.

FIG. 123 shows the configuration having a plurality of input means 9001.This configuration requires the same number of reception means as thatof the input means as well as a plurality of frequency analysis means.However, it does not necessarily require a plurality of adjustment meansnor a plurality of decoding means and it may do with a single adjustmentmeans and a single decoding means by selecting signals to be processedthereby. It should be noted that for simplicity, only a single frequencyanalysis means 9051, a single adjustment 9052, and a single decodingmeans 9053 are shown in FIG. 123 but the present embodiment actuallycomprises the same number of these means as that of the input means asdescribed above.

In the configuration of FIG. 123, the magnitude of a delayed wave andthe delay time can be estimated for each input means because a frequencyanalysis operation is performed for each input means. Therefore, theadjustment means 9052 can select a signal of the best receptionconditions. In addition, an appropriate adjustment can be performed oneach signal through such a transfer function, filtering, orinterpolation technique as described above to decode such a signal inthe decoding means 9053. The decoding means 9053 or the adjustment means9052 can select only signals having a frequency spectrum of goodreception conditions among the frequency-analyzed signals from theseinput means and thus, satisfactory decoding of digital codes can beaccomplished. From the foregoing, the configuration of FIG. 123 cancorrect reception errors by providing a plurality of input means.

It should be noted that in the different digital television broadcastingreceiving devices according to the present invention, the maximum gaincan be achieved with respect to a wave having a different plane ofpolarization by designing each antenna element to have a different anglewhen an antenna consists of a plurality of antenna elements.

Industrial Applicability

As apparent from the foregoing, according to the present invention, ahigh-performance antenna device which can be installed in the proximityof an automobile body or on a plane integrated with an automobile bodyand which can be downsized enough to be located in a narrow space, canbe provided by connecting to a conductive substrate a ground terminal ofan antenna which comprises a plurality of antenna elements, each havingone or two linear conductors with at least one bend or curve or one ortwo spiral linear conductors connected to a single feeding section.

Also, according to the present invention, a high-performance antennadevice which has a capability of correctly receiving verticallypolarized waves, which can be installed in the proximity of anautomobile body or on a plane integrated with an automobile body andwhich can be downsized enough to be located in a narrow space, can beprovided by locating in the proximity of a cylindrical antenna orprinted antenna a planar antenna having an antenna element with at leastone bend or curve.

In a digital television broadcasting receiving device according to thepresent invention, disturbance due to delayed waves contained in inputsignals can be reduced with an improved error rate after demodulation bydelaying input signals immediately after the input or after thereception and then synthesizing them.

Also, in a digital television broadcasting receiving device according tothe present invention, disturbance due to delayed waves can beeliminated properly with an improved error rate after demodulation byestimating the delay time and magnitude of delay from a demodulatedsignal or a signal being demodulated to control such delay and synthesisoperations and then controlling the delay and synthesis operations basedon the estimated delay time and magnitude of delay.

What is claimed is:
 1. An antenna device comprising a conductivesubstrate, two or more antenna elements of different lengths located ina proximity of said conductive substrate, and a coil or zigzag conductorconnected to a common connection at an end of each of said antennaelements, wherein the other end of said coil or zigzag conductor isconnected to said conductive substrate for grounding.
 2. The antennadevice according to claim 1, wherein said coil or zigzag conductor andanother portion of each of said antenna elements are connected togetheron an insulator provided on said conductive substrate.
 3. The antennadevice according to claim 2, wherein said coil or zigzag conductor isdivided into two pieces, said two pieces are connected together on aninsulator provided on said conductive substrate, and a feeding sectionis also connected at where said two pieces are connected.
 4. An antennadevice comprising a conductive substrate, an antenna element located ina proximity of said conductive substrate, and a conductive case providedbetween said antenna element and said conductive substrate and having athrough-hole in a certain place, wherein an end of said antenna elementis connected to said conductive case for grounding, a feeding section isconnected to one of a plurality of insulators provided on saidconductive substrate within said conductive case by using saidthrough-hole, and circuit components are connected between saidplurality of insulators.
 5. An antenna device comprising a planarantenna having at least one bend or curve and an end connected to aconductive substrate and a cylindrical antenna located in a proximity ofsaid planar antenna, wherein an end of said planar antenna is connectedto said conductive substrate at a side of said planar antenna fartherfrom said cylindrical antenna, and wherein a feeding section for saidplanar antenna and a feeding section for said cylindrical antenna arecoupled to a single feeding section through a mixer.
 6. The antennadevice according to claim 5, wherein said planar antenna has a pluralityof antenna elements and said plurality of antenna elements are connectedto a single feeding section.
 7. The antenna device according to claim 6,wherein said plurality of antenna elements are corresponding to aplurality of bands obtained by dividing a target frequency band,respectively, and said antenna elements realize a desired band.
 8. Theantenna device according to claim 7, wherein said cylindrical antenna issupported on said conductive substrate so that it can turn to twodirections orthogonal to each other and is capable of expanding andcontracting in a longitudinal direction.
 9. An antenna device comprisinga planar antenna having at least one antenna element having at least onebend or curve and an end connected to a conductive substrate and aprinted antenna located in a proximity of said planar antenna and havinga zigzag conductive pattern formed on a printed circuit board, whereinsaid planar antenna and said printed antenna exist substantially on thesame plane, and wherein said printed antenna is formed into athree-dimensional shape through one or more bends or curves.
 10. Theantenna device according to claim 9, wherein said printed antenna isformed into a cylindrical shape which surrounds a cylindrical supportmember.
 11. The antenna device according to claim 10, wherein saidprinted antenna is supported on said conductive substrate so that it canturn to two directions orthogonal to each other.
 12. The antenna deviceaccording to claim 11, wherein said conductive substrate is divided intoa substrate portion for said planar antenna and a substrate portion forsaid printed antenna.
 13. The antenna device according to claim 10,wherein said planar antenna is provided between said printed antenna andsaid conductive substrate.
 14. The antenna device according to claim 9,wherein said planar antenna is formed on a board other than a board forsaid printed antenna.
 15. The antenna device according to claim 9,wherein said planar antenna is formed on the board for said printedantenna.
 16. The antenna device according to claim 9, wherein a portionof the board for said printed antenna is formed into a planar shape andsaid planar antenna is formed on the planar shaped board portion. 17.The antenna device according to claim 16, wherein said board portion onwhich said printed antenna is formed is coupled to the board portion onwhich said planar antenna is formed so that it can turn to a directionperpendicular to the board plane.
 18. The antenna device according toclaim 9, wherein said planar antenna has a plurality of antenna elementsand said plurality of antenna elements are connected to a single feedingsection.
 19. The antenna device according to claim 18, wherein saidplurality of antenna elements are corresponding to a plurality of bandsobtained by dividing a target frequency band, respectively, and saidantenna elements realize a desired band.
 20. A digital televisionbroadcasting receiving device comprising an input means which is anantenna device according to claim 18, a delay means for receiving asignal from said input means and delaying it, a synthesis means forsynthesizing a signal from said delay means and a signal from said inputmeans, a reception means for performing frequency conversion on a signalfrom said synthesis means, and a demodulation means for converting asignal from said reception means into a baseband signal, wherein thedelay time used in said delay means and the synthesis ratio used in saidsynthesis means can be established arbitrarily.
 21. A digital televisionproadcasting receiving device according to claim 20, wherein said devicehas a plurality of antenna elements and each antenna element isinstalled so that it can have the maximum gain for a wave of a differentpolarization plane.
 22. A digital television broadcasting receivingdevice comprising an input means which is an antenna device according toclaim 18, a delay means for receiving a signal from said input means anddelaying it, a synthesis means for synthesizing a signal from said delaymeans and a signal from said input means, a reception means forperforming frequency conversion on a signal from said synthesis means, ademodulation means for converting a signal from said reception meansinto a baseband signal, a delayed wave estimation means for receiving asignal indicating the demodulation conditions from said demodulationmeans and estimating a delayed wave contained in a signal from saidinput means, and a synthesis control means for controlling saidsynthesis means and said delay means in accordance with a signal fromsaid delayed wave estimation means, wherein either the signal synthesisratio used in said synthesis means or the delay time used in said delaymeans can be controlled in accordance with a signal from said synthesiscontrol means.
 23. A digital television broadcasting receiving deviceaccording to claim 22, wherein said device has a plurality of antennaelements and each antenna element is installed so that it can have themaximum gain for a wave of a different polarization plane.
 24. A digitaltelevision broadcasting receiving device comprising an input means whichis an antenna device according to claim 18, a reception means forperforming frequency conversion on a signal from said input means, adelay means for receiving a signal from said reception means anddelaying it, a synthesis means for synthesizing a signal from said delaymeans and a signal from said reception means, and a demodulation meansfor converting a signal from said synthesis means into a basebandsignal, wherein the delay time used in said delay means and thesynthesis ratio used in said synthesis means can be establishedarbitrarily.
 25. A digital television broadcasting receiving deviceaccording to claim 24, wherein said device has a plurality of antennaelements and each antenna element is installed so that it can have themaximum gain for a wave of a different polarization plane.
 26. A digitaltelevision broadcasting receiving device comprising an input means whichis an antenna device according to claim 18, a reception means forperforming frequency conversion on a signal from said input means, adelay means for receiving a signal from said reception means anddelaying it, a synthesis means for synthesizing a signal from said delaymeans and a signal from said reception means, a demodulation means forconverting a signal from said synthesis means into a baseband signal, adelayed wave estimation means for receiving a signal indicating thedemodulation conditions from said demodulation means and estimating adelayed wave contained in a signal from said input means, and asynthesis control means for controlling said synthesis means and saiddelay means in accordance with a signal from said delayed waveestimation means, wherein either the signal synthesis ratio used in saidsynthesis means or the delay time used in said delay means can becontrolled in accordance with a signal from said synthesis controlmeans.
 27. A digital television broadcasting receiving device accordingto claim 26, wherein said device has a plurality of antenna elements andeach antenna element is installed so that it can have the maximum gainfor a wave of a different polarization plane.
 28. A digital televisionbroadcasting receiving device comprising an input means which is anantenna device according to claim 18, a reception means for performingfrequency conversion on a signal from said input means, a demodulationmeans for converting a signal from said reception means into a basebandsignal, a delayed wave estimation means for receiving information on thedemodulation conditions from said demodulation means and estimating adelayed wave contained in a signal from said input means, and ademodulation control means for controlling said demodulation means basedon delayed wave information from said delayed wave estimation means,wherein a transfer function to be handled by said demodulation means iscontrolled based on a control signal from said demodulation controlmeans.
 29. A digital television broadcasting receiving device accordingto claim 28, wherein said device has a plurality of antenna elements andeach antenna element is installed so that it can have the maximum gainfor a wave of a different polarization plane.
 30. An antenna devicecomprising a conductive substrate and an antenna element located in aproximity of said conductive substrate, wherein a portion of saidantenna element is formed of a coil or zigzag conductor and an end ofsaid antenna element is connected to said conductive substrate forgrounding, wherein said coil or zigzag conductor is formed at said endof said antenna element and said coil or zigzag conductor and anotherportion of said antenna element are connected together on an insulatorprovided on said conductive substrate, and wherein said coil or zigzagconductor is divided into two pieces, said two pieces are connectedtogether on an insulator provided on said conductive substrate, and afeeding section is also connected at where said two pieces areconnected.
 31. An antenna device comprising a planar antenna having atleast one antenna element having at least one bend or curve and an endconnected to a conductive substrate, and a cylindrical antenna locatedin a proximity of said planar antenna, wherein an end of said planarantenna is connected to said conductive substrate at a side of saidplanar antenna closer to said cylindrical antenna, and wherein a feedingsection for said planar antenna and a feeding section for saidcylindrical antenna are coupled to a single feeding section through amixer.
 32. An antenna device comprising a cylindrical antenna providedin a proximity of a conductive substrate and a planar antenna providedbetween said cylindrical antenna and said conductive substrate andhaving at least one antenna element with at least one bend or curve andan end connected to a conductive substrate, wherein a feeding sectionfor said planar antenna and a feeding section for said cylindricalantenna are coupled to a single feeding section through a mixer.
 33. Anantenna device comprising a planar antenna having at least one antennaelement with at least one bend or curve and a printed antenna having azigzag conductive pattern, both antennas being formed in a proximity ofeach other on the same board, a conductive plate connected to an end ofsaid antenna element and corresponding to said planar antenna, and aninsulation member which insulates said conductive plate from aconductive substrate which is larger than said planar antenna and saidprinted antenna, wherein said planar antenna, said printed antenna, andsaid conductive plate are capable to turn together to a directionperpendicular to the plane of said conductive substrate, wherein saidplanar antenna has a plurality of antenna elements and said plurality ofantenna elements are connected to a single feeding section.